[FIX] Inifite loop on archive_cleanup

Fixes an infinite loop in cleaning up the archive table:

* Shares come in faster than defined in cleanup sleep timeout

Will use an upper limit ID which would match the delete query at the
initial state. Skips archiving if no ID is found (e.g. no rows match the
archive purge conditions).

This will fix #997 once merged.
[FIX] Added more verbose output on failing crons for log
Initial import
[FIX] Use Memcached wrapper on Windows
[FIX] Calling $this from static context

The static function pubKeyToAddress() was calling $this->hash160(). Changed to self::hash160().
Update POOLS.md

Added my pool at spotspool.chriskoeber.com
Merge pull request #1002 from ckoeber/patch-1

Update POOLS.md
Merge pull request #1001 from headzoo/bitcoin_class_fix

Calling $this from static context
Merge pull request #981 from Fredyy90/next

3 small improvments
[CHANGE] Split statistics from Maintenance cron
[FIX] Missing x bit
Merge pull request #999 from headzoo/memcache_fix

Windows Memcache Compatibility
[FIX] Wrong parameter count
[FIX] Admin User Panel for PPS Payouts

This will fix #986 once merged.
[FIX] Disable verbose mode, use cmdline switch instead
[FIX] Typo in Navbar

Fixes #1017 once merged.
Merge pull request #1019 from TheSerapher/issue-1017

[FIX] Typo in Navbar
Merge pull request #1020 from TheSerapher/issue-997

Issue 997
[FIX] Uninitialized var in roundstats class
Merge pull request #1022 from xisi/patch-1

[FIX] Uninitialized var in roundstats class