Add SK53_bulk:load to discarded tags

Added as per consultation with SK53. This tag served a similar purpose to tiger:upload_uuid
Fix unknown entity error on merge (fixes #1618)
Add presets (#1617)
The Facebook share API only accepts a URL. Fixes #1623
Configurable data tile zoom level (#1622)
Merge pull request #1615 from pnorman/patch-2

Add SK53_bulk:load to discarded tags
updated Haitian imagery srcs
childcare amenity

Added childcare amenity tag. Removed conflicting terms in kindergarten tag.
Add PhantomJS step to test instructions
Update mocha and mocha-phantomjs
Fix overlay and scaleExtent for TIGER Alaska/Hawaii overlays
Respect tile layer minimum scaleExtent

Rather than attempting to render an exponential number
of tiles for each z less that the minimum, render none.
Refactor background in preparation for multiple overlays
Support multiple overlay layers
Fix some layer names
cleanup post-save actions.
fix label overflow in toggle lists.
Merge pull request #1630 from awright/master

childcare amenity
Merge pull request #1632 from skorasaurus/haiti-imagery

updated Haitian imagery sources
Remove obsolete validation