Add lyap() and sylvester().
Test for lyap() and sylvester()
and taking some tests out of the inner loop in linalg1.jl
Fix: Scale is real
Doc for lyap() and sylvester().
Avoid explicit transposes
Use chksquare in trsyl!
Merge pull request #7435 from mschauer/lyap

RFC: Lyapunov / Sylvester solver via LAPack xTRSYL