2.3.10: Maintanance Release

Enhancements

• Make fixup of Font Awesome fonts easier for developers
• Let the Wave gauge display units if you wish
• Add change tab event to ui_control output and also accept +1 and -1 to move to next/prev tab - Issue #194
• Let label field be set by a {{msg.property}} (for all widgets with label field) - Issue #220

Fixes

• Unbreak change made in 2.3.9 that dropped all msg with no payload.
  • add passthru flag to button (as per other nodes) - Issue #211
  • fix bad number conversion for slider (and other nodes), if payload not set - Issue #212
    • now returns undefined which leaves UI unchanged, but passes through msg
• Fix bar charts not being cleared properly by [] - Issue #217
• Fix Node-RED crashing on chart bad data input conversion - Issue #218