[IMPROVED] Cronbased global Hash-/Sharerate cache

* [ADDED] New statistic method to fetch all user mining stats
* [ADDED] New global cache to getUserHash/Sharerate calls
* [ADDED] New memcache key for new global cache

Addresses #1471 and may fix it already if no other changes are required.
[FIX] Honor target_bits for hashrate
[FIX] Removed debug output
[FIX] Also honor diff for share difficulties if unset
[REMOVED] Unused stats update
[FIX] Whoopsie SQL
[FIX] SQL again, sigh
[FIX] E-Mail login location
Merge pull request #1477 from MPOS/issue-1476

[FIX] E-Mail login location
Merge pull request #1472 from MPOS/issue-1471

Issue 1471
[ADDED] Comment for DEBUG levels
Merge branch 'next' of github.com:MPOS/php-mpos into next
Update README.md

Added MPOS dev channel
Removed pools
Update README.md

Highlighting of name
Merge changes from TheSerapher's pull/1404 Added re-Captcha to Login Page
no config version inc
Moved csrftoken stuff into a class
added getCurrentIP method to user class
added config option for sitewide csrf protection
specific timing for csrf tokens
clean up pages that use csrftokens
Cleaned up logic of login page csrf protection
added csrf protection to register page