comment typos
correctly report libgettextpo version when major != 0
Add framework for more extensive cPO testing

USECPO environment testing
more detailed py.test results
always notify on failure
Force stored encoding for cPO to UTF-8
Revert use of 'with' statement for python 2.4

this commit should be reversed when 2.4 support is dropped
Attempt to fix buildxpi.py

See
https://groups.google.com/forum/?fromgroups=#!topic/mozilla.dev.l10n/sZrgTqBX6I4