Trying to fix 5+5...

Something weird is happening with Delta if I include \mu and atomic
energy levels into G0_iw.
Fixed 5+5 benchmark.
Fixed spinless benchmark.
Fixed nonint benchmark.
Fixed asymm_bath benchmark.
Fixed anderson benchmark.
Fixed 5BandsKanamori benchmark.

* Did not touch 2ein5bands_segment_dens_dens.py
* g_w.fit_tail() does not work due to issue https://github.com/TRIQS/triqs/issues/99
Added kanamori benchmark.
Added kanamori_offdiag benchmark.
'long_tests' are not needed anymore. Deleted.
Removed 5 band kanamori benchmarks.