Bug fixes in OMA DRM v1 Forward Lock Agent

A couple of fixes in the Forward Lock Agent.
The DRM Framework isn't thread safe so the Forward Lock Agent needs
to protect the private structures.
Base64-encoded content with LF-only instead of CRLF line breaks is now
accepted.
A fix for non-standard boundary characters.
The debug prints are also turned off as default.

Change-Id: I8ab417231380fbe1c371d18a147773ceabc6f69f