Merge pull request #405 from bdon/master

Fix reloading tiles after save
Nodes with changed parents added to difference
Fix difference
Avoid creating lines with < 2 nodes (or areas < 3)
Improve test coverage of ui elements
Merge branch 'master' of github.com:systemed/iD
Test new polygon intersection utils
Fix jshint problems.
Fix undo right after drawing line or area
Refactor lines, keep non-scoped fns out of scope
Merge branch 'master' of github.com:systemed/iD
Add waystack, fix bridge coloring
Remove style and references to it
Fix element drag mousedown is listening to
Improve contrast of selected way nodes. Fixes #371
Merge branch 'master' of github.com:systemed/iD
Request tiles at z15 rather than z16
Name drawing functions so we can profile them
Cache fetch results, higher features limit
Run intersection on difference changes, do not use compact. Fixes #334