[INITIAL] Working version checks

* Check DB structure version, config file version and MPOS core version
* Added new Admin Dashboard to show this core information
* Cronjobs will be disabled if SQL files are not imported
 * SQL files must re-set the db_upgrade_required setting
* Cronjobs will disabled if config files are not updated
 * Simple config file update and version string update will fix this
* Added MPOS status overview
 * Cronjobs and Wallet information for now, others may be added later
* Added new navigation link for Admin Panel Dashboard
* Added new version file
 * Will require updates whenever DB or configs are updated
* Update SQL file that adds the DB_VERSION setting

This will address #1242 and already includes a huge chunk of changes
required to make this work.
Update POOLS.md
Merge pull request #1254 from daygle/patch-2

Update POOLS.md
[FIX] Closing nocache tags

Fixes #1255 once merged.
Merge pull request #1259 from TheSerapher/issue-1255

[FIX] Closing nocache tags
[UPDATE] Check for upgrade later
Update README.md

Added 64bit as requirement if you want proper network hashrates.
[FIX] Caching issues with hybrid templates

* Create subfolders for cache/compiled files for themes

Fixes #1016 once merged.
[FIX] Empty / no template detection
    [UPDATE] Allow deletion of accounts

    Updated backend and theme to be able to deal with deleted accounts

    * Backends will skip any users that have no account_id associated with
      their shares
    * Updated round stats theme to show users as unknown if none can be found

    This will not fully address the issue of account deletion but at least
    wont break the system anymore.
Merge pull request #1264 from TheSerapher/issue-1016

[FIX] Caching issues with hybrid templates
Merge pull request #1246 from TheSerapher/issue-1242

[INITIAL] Working version checks
Move from XML-RPC to JSON-RPC.
Update 000_base_structure.sql

Small hiccup with a new installation, importing the SQL.
Small human error fix.
Merge pull request #1270 from drainx/patch-1

Update 000_base_structure.sql
[FIX] Registration password lenght, API class default time
Merge branch 'next' of https://github.com/TheSerapher/php-mpos into next
[ADDED] Address validation script

Will allow admins to run a validateaddress check via RPC calls against
the coind for all currently available users in the accounts table.

* UNSET for users without a coin_address
* INVALID for addresses not validated against the RPC
* VALID for addresses that validated fine

Just to give people a small tool at hands. Usually addresses are already
validated during account edit, so this script is mostly for those pools
that have not had that change yet and wish to notify their users.

Addresses #1177
[ADDED] Payout fail hint: Wallet covers balance?