SKU: search case insensitive support

As committed in master as well: https://github.com/woothemes/woocommerce/commit/a93cee0cbac395800e9276c596a6329f9968d6c9
Cast term_id as int before using in has_term

As committed in master branch: https://github.com/woothemes/woocommerce/commit/7a21dacf5ba7b6a34468014b0e04b13a34f572c5
Added previous two changes to changelog
RUB currency symbol fixes

As done on master branch:
- https://github.com/woothemes/woocommerce/commit/683d54f957cf4437a213fa8483b580ddae9a5596
- https://github.com/woothemes/woocommerce/commit/1671b1d713f0af4f6a779e85deec005aebd8e98f
esc_js for translatable string in the javascripts

As on master branch:
- https://github.com/woothemes/woocommerce/commit/ba923875a20b66292d4b5c2a4f492506cb4a4a99
- https://github.com/woothemes/woocommerce/commit/3f1bca59ccf006480447d24cec7bbdb4cd7619a1
More esc_js action to prevent errors with translations

As committed on master branch:
- https://github.com/woothemes/woocommerce/commit/38d892b14e26df435e90b2f13f48693d28bc23d4
PayPal button should use 'button' and 'alt' classes.

As committed on master:
- https://github.com/woothemes/woocommerce/commit/00cbde04e5585aa36a3622709d38a87a66ce8757
new status reporting system

new status reporting system, this plugin list is better visually and
very better to read
Have the remove_taxes() method set subtotal to subtotal_ex_tax

As committed on master branch:
- https://github.com/woothemes/woocommerce/commit/742cd3ae364243bdd4e2108d0c10a3458f4893f9
Allow layered nav to work with non pa_ prepended taxonomies

As committed on master branch:
- https://github.com/woothemes/woocommerce/commit/f49bd2cd771d6de3a349a2c882b40c65b56f8eba
Better backwards compatibility with _woocommerce_exclude_image

As committed on master branch:
- https://github.com/woothemes/woocommerce/commit/59db08d70bb3f3f292c5d49e132179ed891f251d
Fix for 0 sale price not returning true in is_on_sale

As committed on master branch:
- https://github.com/woothemes/woocommerce/commit/97ad6e0cda1daf31579b75f464fba9b135ba3549
Failsafe for when get_the_terms() returns false. Closes #3147

Thanks @arminrosu!
Failsafe for when get_the_terms() returns false

As committed on master branch:
- https://github.com/woothemes/woocommerce/commit/7d9d1ee2f03430b9af8d0e48e4fec136398a13ba
Fix error trying to use -> outside object
Post id property is obviously ID, not id
Also pushing product image panel fixes here
Added filter to explicitly hide terms agreement checkbox. Closes #3088
Limit items sent to paypal to 9 Closes #3124.

@coenjacobs
Filter for forcing coutnry Closes #3117.