[CLEANUP] Dashboard number formatting

Cleans up some Ajax data on the dashboard to match the static template
data format. No more jumpy numbers.

Fixes #1354
Merge pull request #1355 from TheSerapher/issue-1354

[CLEANUP] Dashboard number formatting
[CLEANUP] Missed two values
Merge pull request #1356 from TheSerapher/issue-1354

[CLEANUP] Missed two values
[FIX] Typo in modifier
[FIX] wrong percentage calculations in API
[ADDED] Invitation overview to admin dashboard

* Split up dashboard default template into subfiles
* Added new invitation overview
* Updated page file

Fixes #1357 once merged.
Merge pull request #1358 from TheSerapher/issue-1357

[ADDED] Invitation overview to admin dashboard
[IMPROVED] Show static nav hashrate if live off

Fixes #1362 once merged.
Merge pull request #1363 from TheSerapher/issue-1362

[IMPROVED] Show static nav hashrate if live off
[SECURITY] Fixing XSS in PHP_SELF

Fixes #1364 once merged.
Merge pull request #1365 from TheSerapher/issue-1364

[SECURITY] Fixing XSS in PHP_SELF
[FIX] Log SQL errors on invalid checkUserPassword

Fixes #1366 once merged.
Merge pull request #1368 from TheSerapher/issue-1366

[FIX] Log SQL errors on invalid checkUserPassword
[ADDED] last_login timestamp

* [RENAMED] sessionTimeoutStamp to last_login
* [UPDATE] user class to store login time after successful login
* [ADDED] SQL Upgrade file for new column
* [UPDATE] Updated base SQL file

Fixes #1162 once merged.
Merge pull request #1369 from TheSerapher/issue-1162

[ADDED] last_login timestamp
Update README.md

Added new dependency.
[FIX] Custom smarty code HTML
[ADDED] User login overview to admin dashboard

Fixes #1374 once merged
[FIX] Day in seconds wrong