path.c: add function for mp_basename, remove duplicated macros

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@32630 b3059339-0415-0410-9bf9-f77b7e298cf2

Fix crash on path without directories.

Regression introduced in r32630. Patch by Yuriy Kaminskiy yumkam at mail ru.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@32631 b3059339-0415-0410-9bf9-f77b7e298cf2

Handle correctly paths with mixed '/' and '\' in it.

Patch by Yuriy Kaminskiy (yumkam at mail ru)

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@32632 b3059339-0415-0410-9bf9-f77b7e298cf2

Handle ':' on systems with DOS paths: it allows paths like C:foo.avi.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@32642 b3059339-0415-0410-9bf9-f77b7e298cf2