Initial file import for admin panel

* Added isAdmin to user class
 * Run isAdmin on EACH page to ensure admin status hasn't changed
* Added main page with no content
* Added user query page with basic form, no content
Adding working user admin panel to query user DB

* Users are all fetched from the DB
* Each user is assigned special stats
 * Hashrate
 * Shares
 * Balance
 * Est. Payout
 * Est. Donation
* Display in sortable and paginated table

This is not well optimized. Each user stats are grabbed individually
via the stats and transaction classes. It would probably make sense to
expand the statistics class to list a full user list with all statistics
available instead to cover this in a single SQL query.
adding user ID to table
adding number format to admin user query table
fixing sort arrows showing behind text
fixing JS crash when table has no content
Moving from user to statistics class

* This fetches all users and joins with shares table

Should speed up things a fair bit.
sorting does not work with number_format
Merge pull request #98 from TheSerapher/admin-panel

Admin panel