return path in linux, fixes #25

#25 
If you're watching a directory, handlemap contains the path of the directory, and the inotify events give you just the name of the file, so you have to take the directory path from the handlemap and add the filename to it. You can't put fullpath back into handlemap, because that would then be the modified file's full path, and the next modified file would then get an invalid path.
The path variable is just because I need to convert it to a std::vector<char>, at least that's what it originally was, so I kept it to be safe. I'm not very good at C++ though.