Merge pull request #26 from arokem/noise

Noise
Merge branch 'master' of github.com:nipy/dipy into nipy-dipy-master
Merge branch 'master' of github.com:nipy/dipy into nipy-dipy-master
Merge branch 'master' of github.com:nipy/dipy into nipy-dipy-master
DOC more explaination on reslice example
DOC added dependencies file
DOC added a short overview file
DOC updated developers information
DOC corrected first page example
DOC played a bit with the layout
DOC updated developers' information in devel/intro
DOC updated logo, layout and added examples
Added old examples folder as examples_0.5
BF IOError was too dramatic for fetching
DOC modified subscribe.rst, introduction.rst and started working on nii_2_tracks example
DOC new example
DOC corrected sentence in introduction.rst
RF _sphere_odfs is now at viz.mayavi.spheres
NF added line_colors for computing fvtk.line colors
BF avoid returning single points - a streamline should have at least two points