Added the FLENS-LAPACK implementation for heev.
Merge remote-tracking branch 'origin' into public

Conflicts:
	flens/lapack/Makefile
Fixed warning due to eventually unused typedefs
Merge commit '7cb01af7a21aa46a3c932f08f36188d3bdc80b65' into public
Updated optimized BLAS function (Level 1 and 2), speed now comparable with other BLAS implementations