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.
Field myFileChannel removed from OSD_FileNode and introduced to OSD_File as Linux-only along with Windows-only myFileHandle.
Implementation of OSD_File cleaned from redundant type casts; some missing type cases added.
File mode passed to fdopen() corrected in read-write case ("rw" replaced by "w+").
Method OSD_File::Size() now returns Standard_Size to be able to return correct value for large files (on 64-bit platforms only).
