Merge remote-tracking branch 'origin/topic/timw/266-namespaces'

Merge adjustments:

- Preserved original `base_type_no_ref` argument type as ::TypeTag
- Removed superfluous #pragma guard around deprecated TableVal ctor
- Clarify NEWS regarding MetaHook{Pre,Post} deprecations
- Simplify some `::zeek::` qualifications to just `zeek::`
- Prefixed FORWARD_DECLARE_NAMESPACED macro with ZEEK_

* origin/topic/timw/266-namespaces:
  Disable some deprecation diagnostics for GCC
  Rename BroType to Type
  Update NEWS
  Review cleanup
  Move Type types to zeek namespace
  Move Flare/Pipe from the bro namespace to zeek::detail
  Move Attr to the zeek::detail namespace
  Move Trigger into the zeek::detail namespace
  Move ID to the zeek::detail namespace
  Move Anon.h into zeek::detail namespace
  Mark all of the aliased classes in plugin/Plugin.h deprecated, and fix all of the plugins that were using them
  Move all of the base plugin classes into the zeek::plugin namespace
  Expr: move all classes into zeek::detail
  Stmt: move Stmt classes into zeek::detail namespace
  Add utility macro for creating namespaced aliases for classes

src/DbgBreakpoint.h

@@ -3,9 +3,11 @@
 #pragma once
 
 #include <string>
+#include "util.h"
 
 struct ParseLocationRec;
-class Stmt;
+
+ZEEK_FORWARD_DECLARE_NAMESPACED(Stmt, zeek::detail);
 
 enum BreakCode { bcNoHit, bcHit, bcHitAndDelete };
 class DbgBreakpoint {
@@ -20,7 +22,7 @@ public:
 
 	// True if breakpoint could be set; false otherwise
 	bool SetLocation(ParseLocationRec plr, std::string_view loc_str);
-	bool SetLocation(Stmt* stmt);
+	bool SetLocation(zeek::detail::Stmt* stmt);
 	bool SetLocation(double time);
 
 	bool Reset();	// cancel and re-apply bpt when restarting execution
@@ -35,7 +37,7 @@ public:
 	//
 	// NOTE: If it returns a hit, the DbgBreakpoint object will take
 	// appropriate action (e.g., resetting counters).
-	BreakCode ShouldBreak(Stmt* s);
+	BreakCode ShouldBreak(zeek::detail::Stmt* s);
 	BreakCode ShouldBreak(double t);
 
 	const std::string& GetCondition() const	{ return condition; }
@@ -70,7 +72,7 @@ protected:
 	bool enabled;	// ### comment this and next
 	bool temporary;
 
-	Stmt* at_stmt;
+	zeek::detail::Stmt* at_stmt;
 	double at_time;	// break when the virtual time is this
 
 	// Support for conditional and N'th time breakpoints.