Added test for gravmag.polyprism comparing with gravmag.prism
Made gridder.cut return a slice of the arrays instead of a copy
Bug fix in mesher.TesseroidMesh: dims was giving negative dz
Revert "Bug fix in mesher.TesseroidMesh: dims was giving negative dz"

This reverts commit a666b292bbb5e2cb20967510bc6bc7c3e401fc2b.
Added numpy include dirs in setup for windows compilation
Merge branch 'master' into devel
Started refactoring all magnetic codes to use a magnetization vector instead of inc dec
Converted python and cython implementations of prism to new format
Optimized PrismMesh.dump by replacing a generator with numpy slicing. 10x speedup on masked meshes
Updated version to 0.2.dev
Refactored _neprism to use vector magnetization
Finished refactor for gravmag.polyprism to use vector magnetization
Refactored gravmag.sphere to vector magnetization
Mayavi needs to take the norm of a vector magnetization to use as scalar
Updated recipes to use vector magnetization
Updated todo
Made mesher utility funcs take the norm of the physical property before comparing to scalar value
Forgot to add vfilter to last commit
Refactored harvester to use vector magnetization
Modified PrismMesh.dump to generate array fromiter for physical property so it wont break with SparseList