Add contributing document
Update mapState module to support the modeling app.
Fix slider widths defaulting to 100px on page load.
Merge pull request #1579 from kdeloach/topic/modeling-view

Update navbar links in instance_base template
Show "Boundaries" checkbox in Leaflet layer control

This lets users toggle boundaries (e.g. neighborhoods, zip codes) via a checkbox in the Leaflet layers control.
Comment Moderation prototypes

Comment Moderation Page

Needs reviewed by Deb
Merge pull request #1589 from RickMohr/comment-moderation

Comment Moderation prototypes
Merge pull request #1587 from RickMohr/boundaries-checkbox

Show "Boundaries" checkbox in Leaflet layer control
Update scenarios templates CSS.
Merge pull request #1591 from kdeloach/topic/update-scenarios-template

Update scenarios templates CSS.
Integrate comment moderation prototypes

Misc:
* Flag-related stuff is not yet implemented
* rename `comments_review` function as `comment_moderation` to match language used elsewhere
* utility function `detail_link` now supports linking to users and to `MapFeature` subclasses like `Plot`
* Fix initialization of photo review page
Merge pull request #1593 from RickMohr/integrate-comment-moderation

Integrate comment moderation prototypes
Lint removal
Add model and migration rules for TreeFavorite
Merge pull request #1595 from steventlamb/topic/add_tree_favoriting

Add model and migration rules for TreeFavorite
Add leaflet-draw 0.2.2 plugin.

This is for drawing the polygon feature for modeling tree distributions.
Merge pull request #1600 from kdeloach/topic/leaflet-draw

Add leaflet-draw 0.2.2 plugin.
Fontello icon substitution

Fontello icon substitution
Add comment moderation action endpoints

This includes the flag/unflag endpoints for use by the plot detail page
as well as the moderation endpoints for hiding, archiving, and flag
clearing.

I chose to create an EnhancedThreadedCommentFlag model because the
built-in CommentFlag does not support hiding, and I though having our
doubly-inherited comment model link back to another inherited model
would be too confusing, or perhaps impossible.
Change instance comment base endpoint

I made endpoints for flag and unflag and these look most natural as

POST /{instance}/comments/{comment_id}/flag/
POST /{instance}/comments/{comment_id}/unflag/