First prototype of new analyzer framework.

This is a larger internal change that moves the analyzer
infrastructure to a more flexible model where the available analyzers
don't need to be hardcoded at compile time anymore. While currently
they actually still are, this will in the future enable external
analyzer plugins. For now, it does already add the capability to
dynamically enable/disable analyzers from script-land, replacing the
old Analyzer::Available() methods.

There are three major parts going into this:

    - A new plugin infrastructure in src/plugin. This is independent
      of analyzers and will eventually support plugins for other parts
      of Bro as well (think: readers and writers). The goal is that
      plugins can be alternatively compiled in statically or loadead
      dynamically at runtime from a shared library. While the latter
      isn't there yet, there'll be almost no code change for a plugin
      to make it dynamic later (hopefully :)

    - New analyzer infrastructure in src/analyzer. I've moved a number
      of analyzer-related classes here, including Analyzer and DPM;
      the latter now renamed to Analyzer::Manager. More will move here
      later. Currently, there's only one plugin here, which provides
      *all* existing analyzers. We can modularize this further in the
      future (or not).

    - A new script interface in base/framework/analyzer. I think that
      this will eventually replace the dpm framework, but for now
      that's still there as well, though some parts have moved over.

I've also remove the dpd_config table; ports are now configured via
the analyzer framework. For exmaple, for SSH:

    const ports = { 22/tcp } &redef;

    event bro_init() &priority=5
        {
        ...
        Analyzer::register_for_ports(Analyzer::ANALYZER_SSH, ports);
        }

As you can see, the old ANALYZER_SSH constants have more into an enum
in the Analyzer namespace.

This is all hardly tested right now, and not everything works yet.
There's also a lot more cleanup to do (moving more classes around;
removing no longer used functionality; documenting script and C++
interfaces; regression tests). But it seems to generally work with a
small trace at least.

The debug stream "dpm" shows more about the loaded/enabled analyzers.

A new option -N lists loaded plugins and what they provide (including
those compiled in statically; i.e., right now it outputs all the
analyzers).

This is all not cast-in-stone yet, for some things we need to see if
they make sense this way. Feedback welcome.

src/Conn.h

@@ -11,19 +11,22 @@
 #include "Serializer.h"
 #include "PersistenceSerializer.h"
 #include "RuleMatcher.h"
-#include "AnalyzerTags.h"
 #include "IPAddr.h"
 #include "TunnelEncapsulation.h"
 
+#include "analyzer/Tag.h"
+#include "analyzer/Analyzer.h"
+
 class Connection;
 class ConnectionTimer;
 class NetSessions;
 class LoginConn;
 class RuleHdrTest;
 class Specific_RE_Matcher;
-class TransportLayerAnalyzer;
 class RuleEndpointState;
 
+namespace analyzer { class TransportLayerAnalyzer; }
+
 typedef enum {
 	NUL_IN_LINE,
 	SINGULAR_CR,
@@ -47,7 +50,7 @@ static inline int addr_port_canon_lt(const IPAddr& addr1, uint32 p1,
 	return addr1 < addr2 || (addr1 == addr2 && p1 < p2);
 	}
 
-class Analyzer;
+namespace analyzer { class Analyzer; }
 
 class Connection : public BroObj {
 public:
@@ -102,8 +105,9 @@ public:
 
 	void FlipRoles();
 
-	Analyzer* FindAnalyzer(AnalyzerID id);
-	Analyzer* FindAnalyzer(AnalyzerTag::Tag tag);	// find first in tree.
+	analyzer::Analyzer* FindAnalyzer(analyzer::ID id);
+	analyzer::Analyzer* FindAnalyzer(analyzer::Tag tag);	// find first in tree.
+	analyzer::Analyzer* FindAnalyzer(const string& name);	// find first in tree.
 
 	TransportProto ConnTransport() const { return proto; }
 
@@ -161,15 +165,15 @@ public:
 	// Raises a software_version_found event based on the
 	// given string (returns false if it's not parseable).
 	int VersionFoundEvent(const IPAddr& addr, const char* s, int len,
-				Analyzer* analyzer = 0);
+				analyzer::Analyzer* analyzer = 0);
 
 	// Raises a software_unparsed_version_found event.
 	int UnparsedVersionFoundEvent(const IPAddr& addr,
-			const char* full_descr, int len, Analyzer* analyzer);
+			const char* full_descr, int len, analyzer::Analyzer* analyzer);
 
-	void Event(EventHandlerPtr f, Analyzer* analyzer, const char* name = 0);
-	void Event(EventHandlerPtr f, Analyzer* analyzer, Val* v1, Val* v2 = 0);
-	void ConnectionEvent(EventHandlerPtr f, Analyzer* analyzer,
+	void Event(EventHandlerPtr f, analyzer::Analyzer* analyzer, const char* name = 0);
+	void Event(EventHandlerPtr f, analyzer::Analyzer* analyzer, Val* v1, Val* v2 = 0);
+	void ConnectionEvent(EventHandlerPtr f, analyzer::Analyzer* analyzer,
 				val_list* vl);
 
 	void Weird(const char* name, const char* addl = "");
@@ -241,8 +245,8 @@ public:
 	void DeleteTimer(double t);
 
 	// Sets the root of the analyzer tree as well as the primary PIA.
-	void SetRootAnalyzer(TransportLayerAnalyzer* analyzer, PIA* pia);
-	TransportLayerAnalyzer* GetRootAnalyzer()	{ return root_analyzer; }
+	void SetRootAnalyzer(analyzer::TransportLayerAnalyzer* analyzer, PIA* pia);
+	analyzer::TransportLayerAnalyzer* GetRootAnalyzer()	{ return root_analyzer; }
 	PIA* GetPrimaryPIA()	{ return primary_PIA; }
 
 	// Sets the transport protocol in use.
@@ -314,7 +318,7 @@ protected:
 	string history;
 	uint32 hist_seen;
 
-	TransportLayerAnalyzer* root_analyzer;
+	analyzer::TransportLayerAnalyzer* root_analyzer;
 	PIA* primary_PIA;
 
 	uint64 uid;	// Globally unique connection ID.