doc of PYTHONFAULTHANDLER env var: add missing "versionadded" tag
Issue #18441: Make test.support.requires('gui') skip when it should.
Issue #15494: test.support is now a package rather than a module

Also including this change in 3.3 to help avoid spurious conflicts
between the two most active branches.

(Initial patch by Indra Talip)
Close #15415: Factor out temp dir helpers to test.support

Patch by Chris Jerdonek
Issue #18441: Remove check from test_text.py in 3.3,4 (already done in 2.7).
Update gui section of idle test README.