Merge release-test-failures-6247.

Author: glyph

Reviewer: tom.prince

Fixes: #6247

Remove signal handler manipulation from tests, correcting test failures on OS X
10.6.



git-svn-id: svn://svn.twistedmatrix.com/svn/Twisted/trunk@36804 bbbe8e31-12d6-0310-92fd-ac37d47ddeeb
Merge uid-overflow-6201

Author: glyph

Reviewer: exarkun

Fixes: #6201

Address test failures on Red Hat buildbot; change the verified-fake tests for
the pwd module to detect a value for a non-existent UID that is still in the
uid_t range, for Red Hat's bundled patch.



git-svn-id: svn://svn.twistedmatrix.com/svn/Twisted/trunk@36805 bbbe8e31-12d6-0310-92fd-ac37d47ddeeb