winetestbot changes

[Greg Geldorp]

A couple of changes to the test bot:

- Maximize number of powered on VMs (Paul Vriens)
- Make tag prefix for test.winehq.org submissions configurable (Paul Vriens)
- Add support for VMs on multiple hosts, add Windows 95/95B/98/98SE VMs
- Make the "File" field on the "Submit job" page accept longer file names
- Add feedback page

Ge.