Moving a lot of settings from config to adminpanel

* Migrated configuration options to admin panel
* Removed configuration options from config file
* Added help text for each configuration option into panel

Addresses #622 and needs extensive testing by pools. A lot has changed
so pool owners might have to adjust their own templates to match this
new system.
moved motd to website tab
Merge pull request #626 from TheSerapher/issue-622

Issue 622