Address Issue #48 (text-based browsers)

Reference: https://github.com/networkupstools/nut/issues/48#issuecomment-28107101
HCL: make support-level filter show items with a 'higher or equal' level

Reference: https://github.com/networkupstools/nut/issues/48#issuecomment-28134135
HCL: Improve readability of nut_jquery.js
Merge remote-tracking branch 'zykh/iss48css'

Resolves #48 using CSS to render stars for support level