Merge pull request #16 from slayoo/master

draft of parcel.py; theta dry2std / std2dry formulae; cleanups
Merge pull request #17 from slayoo/master

fixing formula for p(rhod, r, T)
Merge pull request #18 from slayoo/master

parcel updates
wip on chem in parcel/lgrngn
Merge https://github.com/trontrytel/libcloudphxx

Conflicts:
	tests/python/lib.cpp