merge r26094, r26292, r26686, r26706, r26861, r26862, r26914, r26933, r26934 and r26947 from trunk to branch 2.6
Dev:
- Replace word "categorie" by "album" in en_UK and fr_FR translation files
- Fix html5 validation errors
- Piwigo 2.6 compliance: Improve confirmation email sending - More accurate when users or admins are set to confirm registrations
- Piwigo 2.6 compliance: Update tablesorter jquery plugin for compliance with jquery v1.10
- Improve confirmation and information email sending workflow
- HTML5 recommandation improvement - Tablesorter and tablepager jquery plugin customization (step 1)
Translations:
Update pt_BR, thanks to : flaviove
Update pt_PT, thanks to : Bridges
Add sk_SK, thanks to : JoeKundlak
Update sk_SK, thanks to : JoeKundlak