Mexican Spanish translation: Translates strings still in English language and improves already translated strings.

Various improvements in the the mexican spanish translation.

See merge request !300

Minor usability issues in settings, lead mapping and Potentials mapping

See merge request !299

Fixes #804 - When i try to resize Widget Sale pipeline bug

See merge request !298

Fixes #785 - vt710 - Dashboard size of the widgets is not saved

See merge request !295

French Trad update

French update :)

See merge request !287

# Conflicts:
#	pkg/vtiger/translations/French/modules/Users.php
#	pkg/vtiger/translations/French/modules/Vtiger.php