DOC: Updated the highlights to promote the release and the upcoming paper
DOC: Fixed the journal promo for the website
Aligned FA pic in the middle of the website
cleaned up old text
Fixed typo
Merge pull request #319 from Garyfallidis/promo_dipy_paper

DOC: Updated the highlights to promote the release and the upcoming paper
ENH: Improved the speed on the pdf_grid method of the shorefit model
ENH: Fixed the non-functional cache of the shore_matrix_pdf on the pdf method
Merge pull request #323 from demianw/shore_pdf_grid_speed_improvement

Shore pdf grid speed improvement
add small and big delta
Merge pull request #327 from maurozucchelli/gradient_delta

add small and big delta