Improve CMAKE BUILD system and OUTPUT PARSING when not all precisions are needed.

Improve CMAKE BUILD system and OUTPUT PARSING when not all precisions are needed.
The following variables will control the precision to be built:
  BUILD_SINGLE
  BUILD_DOUBLE
  BUILD_COMPLEX
  BUILD_COMPLEX16

For mixed precision SINGLE/DOUBLE routines, both BUILD_SINGLE and BUILD_DOUBLE needs to be on.
(same for COMPLEX/COMPLEX16)