Initial commit of file reassembly.
More file reassembly work.

 - The reassembly behavior can be modified per-file by enabling or
   disabling the reassembler and/or modifying the size of the reassembly
   buffer.

 - Changed the file extraction analyzer to use the stream to avoid
   issues with the chunk based approach not immediately triggering
   the file_new event due to mime-type detection delay.  Early chunks
   frequently ended up lost before.

 - Generally things are working now and I'd consider this in testing.
Merge remote-tracking branch 'origin/master' into topic/seth/files-tracking

Conflicts:
	src/Reassem.cc
	src/Reassem.h
	src/analyzer/protocol/tcp/TCP_Reassembler.cc
	testing/btest/Baseline/scripts.base.frameworks.file-analysis.bifs.set_timeout_interval/bro..stdout
	testing/btest/Baseline/scripts.base.frameworks.file-analysis.http.partial-content/b.out
	testing/btest/Baseline/scripts.base.frameworks.file-analysis.http.partial-content/c.out
	testing/btest/Baseline/scripts.base.frameworks.file-analysis.logging/files.log
Merge remote-tracking branch 'origin/master' into topic/seth/files-tracking

Conflicts:
	src/Reassem.cc
	src/Reassem.h
	src/analyzer/protocol/tcp/TCP_Reassembler.cc
	testing/btest/Baseline/scripts.base.frameworks.file-analysis.bifs.set_timeout_interval/bro..stdout
	testing/btest/Baseline/scripts.base.frameworks.file-analysis.http.partial-content/b.out
	testing/btest/Baseline/scripts.base.frameworks.file-analysis.http.partial-content/c.out
	testing/btest/Baseline/scripts.base.frameworks.file-analysis.logging/files.log
Merge remote-tracking branch 'origin/topic/seth/files-tracking' into topic/seth/files-tracking

Conflicts:
	src/Reassem.cc
	src/Reassem.h
	src/analyzer/protocol/tcp/TCP_Reassembler.cc
Merge remote-tracking branch 'origin/master' into topic/seth/files-tracking

Conflicts:
	scripts/base/frameworks/files/main.bro
	src/file_analysis/File.cc
	testing/btest/Baseline/scripts.base.frameworks.file-analysis.actions.data_event/out
Updates the files event api and brings file reassembly up to master.
Merge remote-tracking branch 'origin/topic/seth/files-tracking' into topic/vladg/smb