fixing an assert in donorcell iga
changing bc to open in test_rotating_sphere
re-enabling all test variants in rotating cone test
switching to open bc in paper example 1
removing calls to bcinit and shrinking halo in vctr_alng calls
adding new versions of pi() for integer and mixed-int-rng_t arguments
a small rewrite of boundary conditions (open bc is now based on zero-div condition for vectors and zero-grad condition for scalars; no more bcinit)
Merge https://github.com/slayoo/libmpdataxx