Add a test (failing) for a work tree status.

When thees is an unreadable folder, we should still be able
to enumerate status.
Simplify the test.
Return a specific error for EACCES.
Skip unreadable files for now.
Rename GIT_ENOACCESS -> GIT_EUNREADABLE
Skip unreadable files for now.
Start adding GIT_DELTA_UNREADABLE and GIT_STATUS_WT_UNREADABLE.
Return GIT_FILEMODE_UNREADABLE for files that fail to stat.
Remove errant whitespace.
Simplify the no permission test.
Remove errant newline
Return GIT_DELTA_UNREADABLE for a file with a mode change
Try a value for UNREADABLE that won't get masked out?!
Don't need to duplicate this code.
We do expect the foo path in the nopermissions test
Remove GIT_FILEMODE_NEW as it's unused.

And use 0 for GIT_FILEMODE_UNREADABLE.
Add GIT_STATUS_OPT_INCLUDE_UNREADABLE
Use 'X' for unreadable status.
Fix the no permissions test.
Add GIT_STATUS_OPT_INCLUDE_UNREADABLE_AS_UNTRACKED

and a (failing) test for it.