[ADDED] IDLE Worker Global Switch

Fixes #1921 once merged.
[FIX] Disable monitor option in workers page
[FIX] Disable monitor column on admin pool workers
Merge pull request #1922 from MPOS/disable-worker-notifications

[ADDED] IDLE Worker Global Switch
[ADDED] Settings Runtime Cache
[CLEANUP] Admin Checks

* [REMOVED] SQL Checks, those won't be done since we need SQL to
  login as admin anyway. Are handled in database.inc.php too.
* [CHANGE] Dropped *nix detection since it would not detect Linux PHP_OS
* [IMPROVED] Simply check if we can use socket_create at all, fall back
  to fsockopen if this does not exist.

Not addressing any specific issue, just some cleanup.
Merge pull request #1926 from MPOS/settings-class-cache

[ADDED] Settings Runtime Cache
[IMPROVED] Allow checking against a custom tx fee
[ADDED] Verbose mode
[FIX] Remove static table reference
Merge pull request #1929 from MPOS/fix-hard-coded-table

[FIX] Remove static table reference