[FIX] trade.js: offerCreate - only update angular if not in phase

RT-1961 breaks on tx.on('error'...
[FIX] trade.js: set order mode to trade when user cancels request for secret
[FIX] trade.js: handle errors on offerCancel
Merge pull request #1335 from shekenahglory/develop

[FIX] trade: Fixes and improvements to error handling