Add History lib to use hash for old browsers (IE8+) without native pushState support.
Update README.md
support replace in _updateHash
Merge branch 'browserSupport' of github.com:yahoo/flux-router-component into browserSupport
Merge pull request #4 from yahoo/browserSupport

Add History lib to use hash for old browsers (IE8+) without native pushState support.
Merge branch 'master' of github.com:yahoo/flux-router-component into state

Conflicts:
	lib/RouterMixin.js
	tests/unit/RouterMixin-test.js