Handle pointer-events in CSS Tidy

See upstream commit https://github.com/Automattic/jetpack/commit/be81b17b66dbad0350b1d97bcc00975688032ce7
Use full include paths

See upstream commits:

https://github.com/Automattic/jetpack/commit/cde560693755a4fe4cd4832ba1052db45849cebc

then

https://github.com/Automattic/jetpack/commit/7c9b939941efd1facd44fae9999a06a8aa7e2fb8
Add jshint related changes

Via Automattic upstream commit https://github.com/Automattic/jetpack/commit/866e5367f3a67a1c1a7e07cdda6e09096d6b29a0
Adjust layout for mobile view

Changes via Automattic upstream commit:

https://github.com/Automattic/jetpack/commit/d95d3009d6bc566dc5bad3ad07d33ef3ebe149d6#diff-486f40461255445deb99cd96aa4aca54
Add moz-osx font smoothing as allowed property

Upstream via Automattic
https://github.com/Automattic/jetpack/commit/3969c8ed1333dd4796dd215596bae3be58f23bcc#diff-486f40461255445deb99cd96aa4aca54
Add missing leading slash for includes
Style preview notification bar a bit nicer

Via Automattic upstream
https://github.com/Automattic/jetpack/commit/eabec481dd2c75fe0fb2f17397e391577d63055b
Force LTR in CSS when RTL is being used for code

See upstream from Automattic:
https://github.com/Automattic/jetpack/commit/196e439fb613bcc03098966ea1c6ca7c26123cea
Don't check for migrated CSS revision if it was never migrated

See Automattic upstream commit
https://github.com/Automattic/jetpack/commit/7cff7f0c92a27b046537b502c21e1daa2d99399f#diff-486f40461255445deb99cd96aa4aca54
Merge pull request #7 from washingtonstateuniversity/upstream

[PR] Update with upstream changes through JetPack 3.1-beta