Merged from trunk 6021:6036

Merged from trunk 6021:6036

s/x/xs/ to fix a typo in a variable name.

For consistency, replace multiple os.getcwd() calls with the "mydir"
variable.

Fix stardir and repodir logic from the previous commit.

Avoid a TypeError when commitmessagefile is None.

Use startdir instead of mydir since mydir has a trailing slash which
triggers normalization issues with the dirname function.

Fix more broken commitmessagefile handling.

Fix broken file list handling for FEATUES=sign when only the Manifest
has changed.

Add some sanity checks for file list handling when repolevel < 3.

svn path=/main/branches/prefix/; revision=6081