(timestamps_equal_p): rearrange error-check logic; if we can't stat one or both files, assume timestamps are different.
(timestamps_equal_p): rearrange error-check logic; if we can't stat
one or both files, assume timestamps are different.

(filesizes_definitely_different_p): renamed from filesizes_equal_p.
This question more accurately describes why we're running the test. :)
Again, if we can't stat one or both files, return `different = FALSE'.

(svn_wc__file_modified_p): clean up logic, using routines above.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion