the fmr file wasn't being detected on multivolume targets
the global preset list couldn't be cleared once set
empty global preset file wasn't detected properly either
Change-Id: I9c4b40ed0b6f3dbb0d38eb668fc74a512ea34062
Skins are now more self contained in the skin manager which in the future might allow on demand skin loading (i.e smaller skin buffers)
Skin backdrops are also managed more intelegently (fixes a bug where you can get a crazy backdrop loaded if a .sbs fails to load)
the rockbox_default rescue theme is now called rockbox_failsafe to better express what it actually is.
This commit hopefully/maybe fixes the heavily reported data aborts, so please check if you are getting them
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28073 a1c6a512-1295-4272-9138-f99709370657
