[CLEANUP] Use coin class for worker hashrate calcs

* Worker class was not using coin class for calculations
* Should improve runtime for worker status related queries
[ADDED] Worker totals on Dashboard

* Added worker hashrate sum
* Added refresh interval information to dashboard footer
* Added number formatting to hashrate
Update default.tpl

Corrected spacing when --script is omitted.
Hide Point 5 In Getting Started - SHA256 Coins

Hide irrelevant details in point 5 when SHA256 coin is used.
Scrypt/SHA256 Friendly Changes (Getting Started)

Correctly display miner download links depending on coin used scrypt/SHA256.
Merge pull request #2119 from daygle/patch-1

Update default.tpl
Merge pull request #2120 from daygle/patch-2

Hide Point 5 In Getting Started - SHA256 Coins
Merge pull request #2121 from daygle/patch-3

Scrypt/SHA256 Friendly Changes (Getting Started)
[ADDED] System Date Format string

* [ADDED] New admin panel config option in System
* [UPDATED] Use new date format on all templates

Fixes #2118 once merged.
[FIX] Proper default format
Merge pull request #2122 from MPOS/date-format

[ADDED] System Date format
[UPDATE] cleaner navigation in admin menu
Remove MEGA Crap From Getting Started

What's the go with all the MEGA references? - talk about a way of promoting MEGA? I have removed all references and replaced with reputable links where possible except the CGMiner 3.7.2 download link - I'll try and find a better one and update later.

Reason for this change is because MEGA is prompting users to download the application/join the site.
Merge pull request #2125 from daygle/patch-4

Remove MEGA Crap From Getting Started
Corrected IF Statement End

Sorry just realised if statement was incorrect in my last push - corrected here.
Merge pull request #2126 from daygle/patch-5

Corrected IF Statement End
Merge pull request #2124 from iAmShorty/cleaner-adminmenu

[UPDATE] cleaner navigation in admin menu
[FIX] PHP Notice
Merge branch 'development' of https://github.com/MPOS/php-mpos into development
[FIX] questionmark.png Path