Merge remote-tracking branch 'origin/master' into JSI_bddc

Conflicts:
	src/flow/darcy_flow_mh.cc
Merge branch 'JSI_bddc' of github.com:flow123d/flow123d into JSI_bddc
Merge branch 'master' of github.com:flow123d/flow123d into JSI_bddc
assemble diagonal weights in BDDC

- instead of creating a map with the weights, register them in the
  linsys and then assemble this matrix for loading to BDDCML
Analytical solution for transport problems.

- preliminary text incorporated into documentation
Merge remote-tracking branch 'origin/JSI_bddc'