Fixed #4444 Error in the template htm /usr/local/ispconfig/interface/web/client/templates/reseller_edit_limits.htm

Fixed #4443 Error in the template htm /usr/local/ispconfig/interface/web/client/templates/client_edit_limits.htm

Fixed #4440 Error in the template htm /usr/local/ispconfig/interface/web/client/templates/client_template_edit_limits.htm

Merged language files.

Prevent password managers to overwrite passwords in reseller / client and mailbox edit screen (fixes #4030)

client addition page.

- added limit for letsencrypt and directive snippets selector to client limits
- hide ssl tab if letsencrypt is selected

- Added HHVM to "Default PHP Handler" field (server configuration).
- Fixed "Unable to load the server configuration from database." error when running server.sh.
- Fixed Javascript (accordions weren't working anymore, directive snippets and other placeholders couldn't be added anymore).