feature #731 - Streaming parser + dcerpc parser

Addressed comments from old pr #408, except for 2.

I haven't moved the unittests to a separate file.  Inside the unittests I check for some functions which are defined as static inside the app-layer-dceprc.c.

Also the byte indian flag.  Shall I use the global system level endian values - __BIG_ENDIAN and __LITTLE_ENDIAN, and have both streaming parser and dcerpc use these values?