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

- 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).

- Added fields to client, reseller and website to show when a record was added and by which user

Added: bank account owner field for client

- Random password length: by default, generated passwords will have a length between 10 and 15 characters (instead of a fixed length of 10 characters).

Merged revisions 3049-3051,3053-3054,3058,3070,3074-3077,3082,3086-3088,3091-3092,3094-3095 from stable branch.

(It's used in several countries to identify company)

Implemented: FS#1325 - Option to create remoting user automatically during package installation from repository
Implemented: VAT-ID and customer No. fields for client and reseller.

Fixed: FS#1269 - Field "Max. type of cron jobs (chrooted and full implies url)" in Client limits is misleading