Merge pull request #78 from trontrytel/master

wip on G
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
making some messages FATAL_ERRORS in CMakeLists.txt
fix 3d donorcell formula
working 3d concurrency
Merge pull request #80 from mwarusz/master

thanks!
wip on G (commit with bugs - don't pull it yet!)