License statement text corrected; compiler warnings caused by Bison 2.41 disabled for MSVC; a few other compiler warnings on 54-bit Windows eliminated by appropriate type cast
Wrong license statements corrected in several files.
Copyright and license statements added in XSD and GLSL files.
Copyright year updated in some files.
Obsolete documentation files removed from DrawResources.
Implemented recursive POSIX mutex instead of non-recursive,
Removed SentryNested class, implemented it's features into Sentry class
Added second constructor to Sentry class
