Filled out more license headers

Completed lots of missing documentation
Fixed /** on one-liners, must be /**<

--HG--
extra : convert_revision : svn%3A39bc706e-5318-0410-9160-8a85361fbb7c/trunk%40377

core/msvc8/sourcemod_mm.vcproj

@@ -381,6 +381,10 @@
 				RelativePath="..\..\public\ITextParsers.h"
 				>
 			</File>
+			<File
+				RelativePath="..\..\public\extensions\IThreader.h"
+				>
+			</File>
 		</Filter>
 		<Filter
 			Name="Systems"

core/vm/sp_vm_engine.cpp

@@ -58,6 +58,7 @@ static const char *g_ErrorMsgTable[] =
 	"Native was never bound",
 	"Maximum number of parameters reached",
 	"Native detected error",
+	"Plugin not runnable",
 };
 
 SourcePawnEngine::SourcePawnEngine()