_msg-tracer_ module for node-red

This node-red module adds 2 new features to Node-RED

msg tracing

* Shows a list of nodes where the msg object passed through
* Clicking the node name presents the msg object that node received.
* Clicking the node ID on the list entry locates the node.
* You can re-trace the steps of the msg object by clicking the Left/Right arrows (or setup shortcuts in Node-RED keyboard)

##### View steps and msg contents:
!Observe msg

##### Can be configured to log each step & msg contents to logstash via UDP.
!Logstash Config

Debugging & Breakpoints

!Breakpoints View

##### Adding a breakpoint
1. Select the node(s) you would like to toggle a breakpoint for.
1. Click the red toggle breakpoint button (or keyboard shortcut)

You should see a red circle above the node, indicating a breakpoint is on it.

a new entry in the breakpoints list will be added, clicking it will reveal the relevant node.
1. Once a msg arrives at a node marked with a breakpoint, the msg will halt, and a number indicator will appear above the node, showing how many msg(s) await.


#### Handling paused msg(s)
Once a msg is paused, you have multiple choices for handling it.

##### Release msg
Releases the msg to continue passing through nodes until the end (or the next breakpoint if there is one in it's path).

##### Step msg
The msg will continue one step and will halt on the next node(s).

##### Kill msg
Destroys the msg, denying it from reaching any other nodes.

##### Edit msg
Clicking on any paused msg (node ID) will focus on the receiving node, and popup an editor where you can modify the msg object before deciding what to do with it.

Additionally, you will find "All" buttons for each of the above choices to handle all paused msg(s) with a single click (you can also set keyboard shortcuts for these buttons).