Fixed #4043 3.1 Remote API - client_add: sys_user insert fails if client parameter 'usertheme' is empty

Added "DATE" form type that works like the "DATETIME" type incl. date picker, just without time details.

- Changed default value for expire of ftp user, should have fixed: #3862

Fixed: Issue #3819 v3.1 Unescaped strings in language files after installation vs source throws 500 error

if the filter rule uses "begins with", the regex should be "^$searchterm" instead of " $searchterm"

- ignore limit_client from templates if they don't match client type (client/reseller) (Fixes #3734)