This commit provides a minimal refactoring of the include hierarchy to allow eliminating the LIBSRTP_INTERNAL_BUILD hack added a couple of days ago.  This was tested with gcc, g++, and clang.  Also did a sanity build of the doubango and asterisk downstream projects.
Add support to return the library version number and string via the API.
Removing dead code. Downstream projects should not be using this function. If still needed downstream, include the -DINCLUDE_DEAD_CODE option in CFLAGS.  This resolves issue #41.
* Remove SSRC from dump
* Explaining how to use it
Return 0 when the version string can not be properly parsed.
Prepare for 1.5.0 release.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	test/rtpw.c