[MPLAY32]

[MPLAY32]
Build the Open-File filter mask in runtime, according to the supported extensions and media devices registered in the registry.
Patch by Ricardo Hanke.
CORE-7883 #resolve #comment Committed, with number-of-chars vs. number-of-bytes fixes by me, plus minor modification to build the filter only once when mplay32 is launched, and use a default filter if runtime filter build fails.

svn path=/trunk/; revision=66152