adding cold wallet coin display and setting
Also show negative cold coins

Fixes #660
[IMPROVEMENT] Adding incremental round/user shares

This will address #510. It needs thorough testing and is a WiP but
is a start to improve cron runtime and DB loads.
[IMPROVEMENT] Support incremental contrib shares
Merge pull request #661 from TheSerapher/issue-510

Issue 510
Merge branch 'next' into issue-444-theserapher