Fixes language translation in model header field

Translation in a model header field was broken due to a comparison between string 'true' and boolean true.

This change will also make the model type accept 'yes', '1', 'on' for the translate parameters.
Based on the parent FOFFormHeaderFieldselectable
Merge pull request #265 from Radio-Actif/fix/language-header-model

Fixes language translation in model header field
Fixed issue with filters behavior and between filter
Fixed a syntax error
Merge pull request #266 from Skullbock/development

Fixed issue with filters behavior and between filter
savenew implies addNew


savenew implies addNew. So, same perms requirement to show the button.

Thanks,
Anibal
Merge pull request #267 from anibalsanchez/patch-2

savenew implies addNew
Updating Changelog
Fix navigating submenu sub-items with tab
Merge pull request #268 from twentronix/fix/tabindex

Fix navigating submenu sub-items with tab
Changelog update
Merge pull request #1 from akeeba/development

Getlast