use shared_ptr almost everywhere
import cmath instead of math.h

the os x c compiler was complaining that it couldn't find std::sqrt
Merge branch 'master' into cython_shared_ptr2
Merge pull request #18 from js850/cython_shared_ptr2

cython shared ptr
Merge remote-tracking branch 'origin/master' into lowest_eigenvalue_ts
adapt to shared_ptr changes in pele, mcpele