Faking time in tests, OS X integration tests, selective cache remove

See merge request !14

todo: change the cache behaviour to pass cname cache test

Basic unit tests for rplan

See merge request !13

Cover parent/child zone differences (A/AAAA, NS lameness checks)

See merge request !12

Cover query minimization

See merge request !11

Cover cache reuse

See merge request !10

Code coverage support

See merge request !9

Cleanup tests, no extra records required, bugfixes

Supported integration tests should now pass

See merge request !8