bugfix
fix #149

Conflicts:

	enchant.min.js
fix #150

Conflicts:

	tests/qunit/enchant.js/label-textalign.js
skip tests about webgl on phantomjs
Merge branch 'develop'

Conflicts:
	enchant.min.js
	tests/qunit/enchant.js/label-textalign.js
	tests/qunit/gl.enchant.js/gl.js
reuse old surface in mutabletext if its still ok
fix
behaviour matches unit tests
fix #151
Merge pull request #153 from wise9/feature/resourcesAwareMutableText

Feature/resources aware mutable text
fix #151
fix nineleap.enchant.js
fix Core#currentTime
grunt
fix e.elapsed on 0frame
Label bugfix & optimization
add null case
grunt
bugfix about Label
grunt