[IMPROVED] Optimized IDLE Worker Query

Fixes #811
Merge pull request #820 from TheSerapher/issue-811

[IMPROVED] Optimized IDLE Worker Query
[FIX] Display issues on SHA coins

* [FIX] Estimated shares on various places
* [ADDED] Calculate estimated shares based on network diff in stats
  class
* [UPDATED] Themes updated as needed

Fixes #819 once merged
[FIX] Worker Hashrates in Account -> My Worker
[FIX] Double Payout Detection Fixes Orphan Block Issues

Fixes #715 when merged, for the third time..
Merge pull request #822 from nicoschtein/patch-8

[FIX] Double Payout Detection Fixes Orphan Block Issues
[FIX] Regression bug creating workers

Fixes #823 once merged.
Merge pull request #825 from TheSerapher/issue-823

[FIX] Regression bug creating workers
Merge pull request #821 from TheSerapher/issue-819

[FIX] Display issues on SHA coins
[IMPROVED] Allow for longer monitoring value strings
[ADDED] Error Code Array
[IMRPOVED] Error Notification Mail with new headers
[IMPROVED] Re-factored monitoring criticals/errors

* [ADDED] new monitoring method : endCronjob
* [IMPROVED] Use newly added error codes
* [ADDED] mail notifications, enabled by default
* [ADDED] cron disable on fatal errors with exit code != 0
* [ADDED] Command line swtich: -f = Force running crons even if disabled
* [ADDED] Disabled status in monitoring site

This will improve error handling in our cronjobs. Fatal errors now
require manual intervention by explicityly running crons with the force
option (`-f`). Until they are forced to run, crons will stay disabled.

Fixes #773 once merged
[FIX] Disable mail notifications on disabled crons
[IMPROVED] Added logging failed SQL queries to payouts
[FIX] Double error message in log
[IMPROVED] More testing of error handling, block class
[REFACTOR] Refactored classes for error handling

* [ADDED] More error codes
* [MODIFIED] Class updates to use Base Class all the time
* [MODIFIED] Cronjobs have been slightly adjusted
* [ADDED] More base class features
[FIX] Removed empty error string
[ADDED] Pool name to getpoolstatus API