[FIX] Fixed the retrun type of a fm related function and adjusted the masai test to a changed fm index member

git-svn-id: http://svn.seqan.de/seqan/trunk@14393 e6417c60-b987-48fd-844e-b20f0fcc1017
[DOC] Dox documentation of the store module.

git-svn-id: http://svn.seqan.de/seqan/trunk@14394 e6417c60-b987-48fd-844e-b20f0fcc1017