Set optimizer name in blastest through configure

This makes it possible to just say `make' in the blastest directory.
Add rotm BLAS function

Change-Id: I0a017081e7f39eca850b44810110fd34ad64fe34
Avoid return statement in rotm

The return statement prevented inlining of the function.

Change-Id: I9e75c12287846dd679bf85c61f13d1b1d11f82ab