Add coin icons - Githubissues

This pull requests add coin icons to the web UI. The most popular coins have an icon.

If you dislike all these different colors and much prefer coin icons in black/white, then you can remove the inclusion of "cryptocoins-colors.css".

Places where I did not add icons:

Logfile (I don't want to parse that)
P&L's "Last 24 Hours" and "All" sections (as they didn't even have an exchange icon). But note that I have added an icon on the X axis of the "Per-Coin Graph" section.
P&L's "Daily Graph" dropdown box (as HTML doesn't allow styling option tags; and I wanted to avoid a complex workaround for now)
Alerts (I don't want to parse that)

cryptoeax / arbbot