Grocery Crud Versions Save

- #491: Fixing issue when we use set_read_fields with a column that doesn't exist at the database
- Updating jQuery version to 2.x

• #38: Bug fix: required_fields doesn't work for relation_n_n fields
• #465: Translation for Spanish Uruguay by @mlopezcoria
• #468: Remove PHP 7.3 warnings
• #469: datatables theme - update table fails after delete
• #470: Update Polish translation by @tikky

• #442: Searching in grid with value 0 is not working
• #458: Updated Lithuanian language by @dgvirtual
• #463: Updated Spanish language by @CarlosPinedaT
• Security fix

• #441 Adding clone functionality - contribution from @portapipe

• #211: Bug if use where clause and try to "search all" the fields
• #432: Bootstrap Theme issues with filtering when we are using set_relation with multiple fields
• #353: Adding callback_read_field function
• #433: Preview click with fancybox to work the same across all the themes

• #420: set_relation with brackets is causing ambiguous column name when the field name exists at the basic table
• #413: Unexpected error when there are non english chars and a datetime field as column
• #406: Export button to work without the need of a popup window or new tab
• Clean-up redundant JavaScript load if it is not required.
• Remove Export as a flash plugin for security reasons and instead add a download link

• Urgent release only for the bug of CI 3.1.3
• #382: Adding custom error message for set_rules()
• Two new lang strings for the multiple delete confirmation
• #388: Chosen select have 100% width at flexigrid theme

• #382: Adding custom error message for set_rules()
• Two new lang strings for the multiple delete confirmation
• #388: Chosen select have 100% width at flexigrid theme

• #331: Have a configurable XSS clean option to prevent XSS attacks
• #370: A faster way to calculate the totals

• Unset bootstrap with more CSS unsets
• Languages updates (Portuguese, Italian, Spanish)
• #367: Missing translation for Search {column_name}