Potential fix for PHP Warning

This should fix #327
Fixing PHP Warnings in Registration page

* Fix API Key generation not using SALT when creating hash
 * This should not affect existing API keys since hashes are compared
* Fix PHP Warning for RECAPTCHA if disabled

Fixes #328
Merge pull request #333 from TheSerapher/issue-328

Fixing PHP Warnings in Registration page
Merge pull request #334 from TheSerapher/issue-327

Potential fix for PHP Warning
Starting to add pools to README/POOLS file
Update POOLS.md
Show nethash rate in MHash/s not GHash/s

* Easier to compare directly with pool hashrate
* Better display format for low nethash rate coins

Fixes #331
Merge pull request #335 from TheSerapher/issue-331

Show nethash rate in MHash/s not GHash/s
Merge pull request #340 from TheSerapher/issue-303

Issue 303
Fixing strict PHP warnings when registering a user

Fixes #329
Merge pull request #342 from TheSerapher/issue-329

Fixing strict PHP warnings when registering a user
Merge pull request #2 from TheSerapher/next

Next