Add exception handing to Change node

Adding exception handling to the change node to prevent node-RED from
crashing on invalid regular expressions eg. “*kW” (missing escape
before the asterix)
Added validation logic to Change editor for validity of regular expressions

This change adds input validation to the gui of Change Nodes to prevent
the user from unintentionally entering an invalid regular expression.
The user will be notified on the specific error code to help resolve
the issue.
merge from upstream
undo my changes to the Change node; revert to original

undo the local changes to the Change node to get back aligned with the
master tree
Make log message in invalid regular expressions more verbose

Make logging of erratic regular expressions more verbose to help
identification and resolving of the configuration issue:

eg.:
old: 24 Dec 18:40:09 - [error] [change:Strip kW] Invalid regex: *kW
new: 24 Dec 18:40:09 - [error] [change:Strip kW] Invalid regular
expression: /*kW/: Nothing to repeat

old: 24 Dec 20:15:57 - [error] [change:Strip kW] Invalid regex: *kW
new: 24 Dec 20:15:57 - [error] [change:Strip kW] Invalid regular
expression: /[kW/: Unterminated character class
Add validation to Change node editor for invalid regex

This change adds input validation to the gui of Change Nodes to prevent
the user from unintentionally entering an invalid regular expression
(in case the ‘use regular expressions’  option is enabled).

The user will be notified (using the RED notification mechanism) on the
specific error code to help resolve the issue.
Disable the notification for the Change node editor

Disable the notification on the Change node.
Once the infrastructure for validation error messages is implemented
this can be re-enabled and retrofitted to the
new structure.
Merge pull request #127 from fvdpol/master

Add validation to the Change node 'from' field