issue2551334 - get test suite running under windows

Fix test_cgi under windows. Few classes of errors:

1) comparing paths with a/b (unix) to a\b (windows). Use normpath to
   fix it. Also change regexps used for path matching to use either
   \ or / for directory separators.

2) database not being closed preventing deletion of test case
   directory. Windows doesn't allow deletion of open files.
   In some cases replaced calling client.inner_mail() with main()
   because main() makes sure to close the database. In other cases
   assigned self.db = client.db beacuse client reopens the database
   and closes the original self.db. Reassigning allows tearDown to
   close the last opened handle to a db.

3) commit the admin password to the database. If it's not commited
   calling the code sometimes comes up with a different admin
   password. Not sure why we don't see this on linux.

4) run commit() on database so that sqlite databases can be closed
   and deleted. Unit tests don't call the main entry points that
   have finally clauses to close the databases properly, so do it in
   the test.

5) split tests that try to resolve symbolic links in the template
   directory to a separate method. Under windows user needs special
   permissions to creae symbolic links, so I report the method is
   skipped if creating a link fails.

Author: rouilj