Update FEST
Move UI test harness classes to plugins module
Fix a couple of broken ui unit tests

Change-Id: I12624ecd8c568294e06c304faf522bdc1da366c2
Reviewed-on: http://gerrit.dmdirc.com/454
Reviewed-by: Shane Mc Cormack <shane@dmdirc.com>
Tested-by: Shane Mc Cormack <shane@dmdirc.com>