Add rootpy.interactive.interact() to spawn an (I)Python console
scripts/rootpy: Rename the sum() function hsum() so as not to interfere with interactive console
Fix stack depth
Merge pull request #230 from pwaller/interact

Add new interact() function and small fixes
Add rootpy.math.linalg.matrix.as_numpy for TMatrix->numpy.matrix
matrix.py/as_numpy: docstring, remove useless import
Merge pull request #233 from pwaller/matrix-as-numpy

Add rootpy.math.linalg.matrix.as_numpy for TMatrix->numpy.matrix
respect style's default canvas dimensions in Canvas.__init__