OPT: Modified dipy.core.sphere_stats.random_uniform_on_sphere, see issue 181.
RF - fix disperse_charges so that a large constant does not cause the potential to blow up.
BF: Changed from numpy.hstack to numpy.vstack as suggested by MrBago.
DOC: Added a 'Notes' and a 'References' section to dipy.core.sphere_stats.random_uniform_on_sphere, as per Numpy/Scipy documentation style guidelines.
BF - fix fit-tensor handling of file extensions and mask=none
BF - set default smooth in shm to .006
BF - fix scaling for Csa Model
NF - added gfa attribute to SphHarmFit class
DOC - clarify docs for SphHarmModel
Merge pull request #183 from ecaruyer/fix-for-issue-181

OPT: Modified dipy.core.sphere_stats.random_uniform_on_sphere, cf issue #181
Merge pull request #182 from MrBago/disp-charges-constant

RF - fix disperse_charges so that a large constant does not cause the po...
RF - minor cleanup
Merge pull request #190 from MrBago/bf-fit-tensor

BF - fix fit-tensor handling of file extensions and mask=none
RF - move const to class level
DOC: add reference section to ProbabilisticOdfWeightedTracker
DOC: adress comments by Stefan about acronym and reference formatting
Merge pull request #196 from mekman/add_ref

DOC: add reference section to ProbabilisticOdfWeightedTracker
DOC - feedback from pull requset 191
FIX: testfail due to Non-ASCII character \xe2
Merge pull request #189 from MrBago/shm-small-fixes

BUG - Small fixes to SHM