#430. Changed selector options and removed unnecessary js functional.
#430. Fixed bulk editor category showing.
#430. Added removing of all category prices on reset all, added set all prices and global price to 0 on free all.
#430. Added case for free action with category selected.
#430. Fixed category with exists price not setted to zero.
#430. Minor changes in comments.
#430 some formal adjustments
#430. Backmerge with master.
Merge branch 'master' into feature/430_revise_available_options_in_bulk_editor
#430. Major refactoring, fixed various errors, separated global actions and posts actions, added validation for 'set all posts' action.
#430 Fix prices below 0.05 and price displayed in flash message
#430. Removed format_number function usage from ensure_valid_price.
#430. Merge with last changes.
Contextual Help for Bulk Price Editor

Added the contextual help for the bulk price editor and the according translations.
Merge branch 'feature/430_revise_available_options_in_bulk_editor' of https://github.com/laterpay/laterpay-wordpress-plugin into feature/430_revise_available_options_in_bulk_editor
Minor Fix Contextual Help

Fixed the contextual help and the according translation: Clarified that prices < 0.05 EUR will be changed to 0.05 EUR instead of 0.00 EUR.
#430. Fixed global price revenue model, fixed disabled change amount select on increase decrease.
#430 Re-built assets
Merge pull request #440 from laterpay/feature/430_revise_available_options_in_bulk_editor

Feature/430 revise available options in bulk editor
Adjusted screenshot descriptions

Adjusted the descriptions for the screenshots on the wordpress.org plugin page.