WIP (DO NOT MERGE) MAGN-4745 Colour the nodes according to the delta state

http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-4745

# What:

- [x] Colors the AST of nodes according to whether the AST is added, modified, deleted, or clean, as set in the SyncDataManager. This is available using the Debug - > Show Debug ASTs menu option.  (DONE, but requires update pending replacement of ASTCache in #2611)
- [x] Add a window which shows the dumped IL during execution. This is available using the Debug -> Show Execution Log (DONE)
- [ ] Colors the borders of nodes according to whether their AST has been built for execution (pending #2611)

# How:

Add a LiveRunnerViewModel which handles events raised by SyncDataManager and ChangeSetComputer. Those two classes are made to implement INotifyPropertyChanged, which is mono-safe. Sets the TextWriter for ProtoCore.Core.AsmOutput in the LiveRunnerViewModel to a text writer of our own devising which raises writing events which trigger property change notifications for the UI. 

Requires Merge:

- [ ] Revit 2015
 
PTAL:
@junmendoza 
@lukechurch 
@Steell (FYI)

![image](https://cloud.githubusercontent.com/assets/1139788/4552467/9a816e94-4e84-11e4-9e9e-c05a7c80fe01.png)