Added unit tests for algorithm::xml_encode()

Updated ChangeLog & bumped version to 5.0.3 for RC
Function to set content given a buffer pointer and size
STREAM-549 Function to set content given a buffer pointer and size
Merge pull request #4 in RND/pion from STREAM-549 to develop

# By Vinu
# Via Vinu
* commit '7c88e414604bef072bc6b846263042fd81a480a4':
  STREAM-549 Function to set content given a buffer pointer and size
  Function to set content given a buffer pointer and size
PION-1314: Attributes in Set-Cookie header should not be quoted

Reported by sba via pion-users list
Merge remote-tracking branch 'upstream/develop' into develop

Conflicts:
	src/http_types.cpp