Improve/fix morphology section
Merge pull request #10 from jni/mor-fix

Improve/fix morphology section
Clarify edges and gradients
Add solutions notebook
Tweak slide-types
Minor fixes to intro
Draw H in slightly more visible spot
Rename filter module import and gradients
Simplify Hough-circle solution
Remove solutions so we can merge with master
Merge pull request #11 from scikit-image/rename/filter_and_gradients

Rename filter and gradients
Merge branch 'master' of github.com:scikit-image/skimage-tutorials
Split watershed section into smaller bites
Merge pull request #12 from jni/ws-split

Split watershed section into smaller bites