[BeOS] - commit - Selectable file types.

[Christopher Plymire]

This commit allows selectable file types on the BeOS version via a menu 
beside the file name.

Files Modified:
abi/src/af/xap/beos/xap_BeOSDlg_FileOpenSaveAs.h
abi/src/af/xap/beos/xap_BeOSDlg_FileOpenSaveAs.cpp

- Christopher