Merge pull request #1 from PrestaShop/master

Merge Head
Merge remote-tracking branch 'upstream/master'
TEXTM-140 : fixed problem connected with missing products in products selection table when creating new project. Also found bug connected with uncleared filtering and fixed it.
Merge pull request #3 from remixaz/master

TEXTM-140 : fixed problem connected with missing products in products se...
lowered amount of API calls, using singleton design pattern on textmaster.class.php
undefined array element 'status' warning in project creation form
Merge pull request #4 from giedriusStan/master

fixed performance issues
TEXTM-145 : When Multiple authors were selected then in final project creation step single author was shown as selected. Fixed.
Adaptation code for Prestashop validation
Adaptation code for Prestashop validation
Adaptation code for Prestashop validation
Adaptation code for Prestashop validation
Adaptation code for Prestashop validation
Adaptation code for Prestashop validation
Adaptation code for Prestashop validation
Adaptation code for Prestashop validation
Adaptation code for Prestashop validation
Adaptation code for Prestashop validation
Adaptation code for Prestashop validation
Adaptation code for Prestashop validation