add japanese contents for assync javascript programming
translated title & supported browser
translate 1st section
translate 2nd section
translate 3rd section
translate 4th section
translate half of 5th section
translate 5th section
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translate last section
polished translate
Add PageVisibilityAPI tutorial
Updated with practical examples

Added practical examples, re-arranged the structure a bit. Still need
to add GA example.
Add Google Analytics example

Show how to defer page view tracking when a browser is pre-rendering
the page
Revisions to the constraint validation post based on feedback from @aFarkas, comments, and Twitter.
Merge pull request #208 from tjvantoll/constraint-validation-tutorial

Revisions to the constraint validation post based on feedback from @aFar...
improve translation

refs #195 Based on @agektmr's review
Use helper functions for properties and events

Minimize the amount of prefix checking via helper functions to make the
code examples clearer.
Merge branch 'master' of https://github.com/joemarini/www.html5rocks.com into joemarini-master

fixed conflicts:
	database/profiles.yaml
	database/tutorials.yaml
Tweaks to Joe's article