Build fixes for CMake

- Disable incremental linking on on MSVC with OPT:REF
  We should've disabled this a while ago, except CMake keeps removing it
  from our flags. To overcome this, I decided to spell 'incremental' in an
  alternate case form which as of now is not recognized by CMake.

- disable strict aliasing universally for gcc

- always define HAVE_COUCHBASEMOCK
  For some reason this ended up being no longer defined. It is needed so
  that automated testing against the mock can happen with `check-all`

Change-Id: Ia323dad412b289c633e0f38112b079ec98d996b4
Reviewed-on: http://review.couchbase.org/36414
Reviewed-by: Brett Lawson <brett19@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>