Symlink handling could be improved

I use a lot of symbolic links in my music collection to navigate between albums, genres etc. This doesn't work with MOC because MOC does not remove loops when resolving a link. For example, I have symlinks between albums and artists organized as follows:

albums/X/artist_Y -> ../../artists/Y
artists/Y/album_X -> ../../album/X

Each time I navigate between the two directories, MOC's "current directory" becomes longer, and at some point MOC crashes.

An simple solution, which works fine for me, is to normalize the directory using realpath() in go_to_dir().