When using snprintf or fgets, etc, do not use PATH_MAX directly as the size

When using snprintf or fgets, etc, do not use PATH_MAX directly as the size
of the variable...use sizeof() compiler directive (lots of these).

Do not free 'realpath' in efreet_menu if we are going to try and print out
it's value.

If we find 'realpath' in the merged_menus hash, and we are going to return,
then free the realpath variable.

SVN revision: 44699