Fixed invalid check in `position_of_last_directory_separator' where on Windows we wrongly checked that a character was not a directory separator. This fixes a new test case of test#path002.


git-svn-id: https://freeelks.svn.sourceforge.net/svnroot/freeelks/trunk@682 6d4a7a74-6026-0410-acef-abb7cea3cd6d
Updated postcondition `rename_path' to match the implementation and compare strings and not a string instance with a path instance.


git-svn-id: https://freeelks.svn.sourceforge.net/svnroot/freeelks/trunk@683 6d4a7a74-6026-0410-acef-abb7cea3cd6d