Fix tests expecting specific resource IDs

Fix tests expecting specific resource IDs

When Wincache or APC are installed, the resource IDs are not the same.
This is because Wincache takes a few resource objects for itself.  As a
result, these tests become false positives.

On Windows boxes, the microtime precision is not granular enough
to reliably register a difference if two calls to uniqid() are made
concurrently.  This is a fix to the uniqid() test to avoid the false
positive when run on Windows machines.  Also, added a test to exercise
the 'more_entropy' variant of uniqid().