Use CMSIS timer library for system clock on LPC17xx.
Use CMSIS/CDL library for delay timer, too.
Fix a regression that caused only 1 signal per message to be handled.
Only retreive signals from XML if the message is the one we intended.

Fixed #1267 in Redmine.
Merge branch 'next' into 60-can-status
Store system clock as milliseconds, not microseconds.