[IMPROVED] Added donation minimum and rounding

* [ADDED] Config option `$config['donate_threshold']['min'] = 1;`
* [VERSION] Incremented config file version to `0.0.6`
* [CHANGED] Round donations to at least two digits
* [CHANGED] Honor minimum set pool donation percentage
* [UPDATED] Account edit template

Fixes #1475 once merged
Merge pull request #1567 from MPOS/donation-percentage

[IMPROVED] Added donation minimum and rounding