Added local variance estimation
Added option to use full volume or only non zero voxels
Added tests
stuff
removed estimate_noise
Added estimate sigma
removed estimate sigma test
added estimate sigma test
corrected copy paste error in filename
removed scipy convolve import
Added scipy convolve import
fixed test import
Update test_noise_estimate.py
Intermediate convolve array to prevent overflow
Merge branch 'local_variance' of github.com:samuelstjean/dipy into local_variance
Removed randomly added files
BF: fix writing history to file in Python 3

Need to open file in binary mode to save text, strangely.
Merge pull request #433 from samuelstjean/local_variance

Added local variance estimation
Merge pull request #462 from matthew-brett/fix-for-py3-streams

BF: fix writing history to file in Python 3
DOC: update RESTORE tutorial to use new noise estimation.