Spanish translation update

Spanish translation extended and improved.
Duplicate capability hook
Update ro_RO frontend translations
PayPal button should use 'button' and 'alt' classes. Closes #3096
gitignore
Have the remove_taxes() method set subtotal to subtotal_ex_tax
Make date in Customers Order Notes localized

Added missing localization code to line 37.
Fix for 0 sale price not returning true in is_on_sale
Allow layered nav to work with non pa_ prepended taxonomies
Better backwards compatibility with _woocommerce_exclude_image

@coenjacobs
Merge pull request #3131 from kloon/master

Fix 0 sale price not returning true in is_on_sale
Readme for #3131
Variation Bulk Edit - Increase/Decrease prices by fixed or percentage values
Changed MyException to Exception, no MyException class in WooCommerce
Splitting the CSS #2785
Merge pull request #3106 from a1ur3l/master

Update ro_RO translation
Merge pull request #3114 from pablolaguna/master

Spanish translation
Merge pull request #3134 from kloon/master

Variations bulk edit increase/decrease prices by fixed or percentage values and MyException fix
Merge pull request #3121 from sybarite/master

Pull request to fix issue #3120
Merge pull request #3078 from Geczy/master

Duplicate capability hook