Update utils.py

Fixed -2250
Fixed #2250
Add Release History to the sidebar

Closes #2269
Made more better
Merge pull request #2271 from mikecool1000/fix-2250

Fixed #2250
Merge pull request #2273 from sigmavirus24/add-changelog-to-sidebar

Add Release History to the sidebar
Update sidebarintro.html

Fix issue #2279. "Gittip" changed to "Gratipay". Tip button extended from 48px to 60px.
Merge pull request #2282 from morganthrapp/patch-1

Update sidebarintro.html