Fixed transitions on some Android 4.1 devices

On some devices (tested on a Samsung Galaxy S2), Android 4.1 is
erroneously reporting to support unprefixed transitions events, while
it’s in fact not implemented.

The solution is to test for the prefixed version first. The
WebKit-prefixed event has been moved on top of the tested events, and
while the Object properties order is not guaranteed in JavaScript (ES3,
section 4.3.3), it is the case in the targeted browser.
Merge pull request #249 from bpierre/android-41-fix

Fixed transitions on some Android 4.1 devices
fix tests for #249
fix #251 get/set for keypaths with brackets
allow one-time interpolation inside all directives
Contributing guide: issue reporting checklist
Merge pull request #261 from bpierre/contribution-guide

Contributing guide update
double clone bug

The previous statement already cloned the fragment
strip newline at end
Merge pull request #267 from dyu/dev

double clone bug
fix #253 attribute names with colons
Small performance fixes

According to the discussion in #262
Merge pull request #271 from bpierre/perf-fixes

Performance fixes
address #278 v-style with important priority
fix #276 and #281 child vms removed before parent transition finishes
give v-with higest priority among normal directives (fix #282)
update dev dependencies
fix #288 v-with misbehaving with $watch
fix #284 lazy option not inherited
address #290 v-on on iframes