adding two TODOs in concurrs
removing traces of bcinit() from bconds; adding the deriv flag to fill_halos_sclr(); renaming xchng() -> xchng_sclr()
removing unused second argument of xchng()
fix for previous commit:)
moving xchng() from shallow_water into mpdata_rhs::update_rhs() + TODO for valid/invalid flagging mechanism
Merge pull request #121 from slayoo/master

deriv flag in xchng_sclr(); removing xchng() from shallow_water; bcinit() cleanup; ...