Add "Previously Recorded" menu and keybinding access to various
screens.

This change brings up a filtered variant of Previously Recorded screen
using the currently selected program.  It is based on patches from amb
at gedanken.org.uk with fixes and enhancements from me.

Closes #11496
Have 'make test' actually compile the tests before running them
Use QTEST_APPLESS_MAIN for MythTimer test.
Add starter mythsystem unit test.
Use initialisation list for UIGTCon copy constructor
Ensure testrec is deleted in TV::HandleStateChange() if the recorder proves to be invalid. Should never have happened in practice. Coverity 1023891
convert (void)parameter to anonymous parameters
Initialise ret to kCategoryNone in QueryCategoryType. Fixes coverity issue 1023897
Rework renderer selection to only allow one match per round

Pointed out by coverty detecting a potential leak.
Merge remote-tracking branch 'upstream/master'