params_t cleanup (preparing for passing nx, ny, n_eqs, n_iter, ... via params_t
wip on G
G allocatio, first G formulae
Merge github.com:slayoo/libmpdataxx

Conflicts:
	libmpdata++/solvers/adv/detail/mpdata_common.hpp
	libmpdata++/solvers/adv/detail/solver_1d.hpp
Merge pull request #78 from trontrytel/master

wip on G
adding a test for nug option
making n_eqs a params field (was a template paprameter)
moving n_iters to params
merge with Ania's big-G-related changes
moving nx,ny,nz from concurr ctors to params
inheriting ctors in bconds
adding C++11 and Blitz checks in CmakeLists.txt
fixing the nug test