Initial rework of packet filter framework.

- Large rework on packet filter framework to make many things easier.
   - Removed the PacketFilter::all_packets variable because it was confusing.
   - New variable (PacketFilter::enable_auto_protocol_capture_filters) to re-enable the old filtering model of only sniffing ports for analyzed protocols.
   - In progress plugin model for adding filtering mechanisms.
   - New default single item for capture_filters = { ["default"] = PacketFilter::default_capture_filter };
   - Mechanism and helper functions to "shunt" traffic with filters.

- Created the Protocols framework to assist with reworking how base protocol scripts are registered with DPD and other things.
   - Protocols framework creates BPF filters for registered analyzers. (if using PacketFilter framework in that mode).

scripts/base/protocols/ftp/main.bro

@@ -3,10 +3,12 @@
 ##! will take on the full path that the client is at along with the requested 
 ##! file name.
 
+@load base/frameworks/protocols
 @load ./utils-commands
 @load base/utils/paths
 @load base/utils/numbers
 
+
 module FTP;
 
 export {
@@ -92,12 +94,10 @@ redef record connection += {
 	ftp: Info &optional;
 };
 
-# Configure DPD
-const ports = { 21/tcp } &redef;
-redef capture_filters += { ["ftp"] = "port 21" };
-redef dpd_config += { [ANALYZER_FTP] = [$ports = ports] };
-
-redef likely_server_ports += { 21/tcp };
+global analyzers = { ANALYZER_FTP };
+redef Protocols::analyzer_map["FTP"] = analyzers;
+global ports = { 21/tcp };
+redef Protocols::common_ports["FTP"] = ports;
 
 # Establish the variable for tracking expected connections.
 global ftp_data_expected: table[addr, port] of Info &create_expire=5mins;