Redirect more source links to work page when possible

Related to #1866. Fixes #2021.
#2024: Add artcomm metatag
fixes #1647
#1875: Position dialog near right of screen instead of center
#1875: Add pin button
#1875: Fix bug when resizing pinned dialog
fixes #2035
Potential fix for #1526
fixes #2005
Merge branch 'mobile-stylesheet'
refactor
link to mobile versions
fixes #2037
fixes #2039
Use ajax form for artist commentary

This prevents the parameters (eg. ?tags=whatever) from being eaten on
submit.
Merge branch 'master' of https://github.com/r888888888/danbooru
Add commentary changes link to profiles
fixes #2041
Don't make commentary dialog block rest of screen
#1866: Improve deviantart source redirect matching