Fix another instance of filename encoding problems

Fix another instance of filename encoding problems

	* src/support/filetools.h
	(fileSearch): change return value type to vector<FileName>

	* src/support/filetools.C
	(dirList): Convert filenames from the file system encoding

	* src/converter.C
	(Converters::move): Adjust to dirList interface change

	* src/support/filename.[Ch]
	(FileName::fromFilesystemEncoding): New static method

	* src/client/client.C: Add comments about filename encoding

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@16362 a592a061-630c-0410-9148-cb99ea01b6c8