Use host's functions for file i/o directly (open(), close() ,etc.), not the sim_* variants.
Some dir functions need to be wrapped still because we need to cache the parents dir's path (host's dirent doesn't let us know).
For the same reason (incompatibility) with host's dirent) detach some members from Rockbox' dirent struct and put it into an extra one,
the values can be retrieved via the new dir_get_info().
Get rid of the sim_ prefix for sleep as well and change the signature to unix sleep().
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27968 a1c6a512-1295-4272-9138-f99709370657
