1:
* when a blendfile gets loaded, paths are corrected with OS specific slashes (see blender.c)
* made available BLI_char_switch(char *string, char from, char to)
* made available BLI_clean(char *string);. This function should be called whenever you're doing path stuff, so paths are correctly saved, and thus avoiding other path functions stopping to work
2:
* relative paths work now in sequencer too (due to slash mess that didn't work all too well).