- replace all hardcoded strrchr functions (used to get extension / file
name only) with path helper functions (found a few bugs in the process)
- split VFS-independent path helper functions into lib/path_util (allows
including by other files without pulling in entire VFS)
- renamed pp_* functions path_package_*
- split remaining path helper functions into lib/res/file/path
- vfs: split should-reload logic out of vfs_reload_changed_files
- lib: add comments to rand/xrand
This was SVN commit r3796.
