Display kernel panic message when graph update fails

##### Background
Here are the changes going into this pull request:

- Unhandled exception from ```LiveRunnerServices.UpdateGraph``` are shown on a modal dialog
- ```GenericTaskDialog``` has been updated to display exception information
- Crash and obsolete file icons are refreshed

##### Preview
This is how the dialog currently looks like:
![updated-panic-dialog](https://cloud.githubusercontent.com/assets/5086849/2535740/3e1a3cf6-b593-11e3-8a7b-468296e5ea5f.png)

This is how it previously looked like:
![kernel-panic-dialog](https://cloud.githubusercontent.com/assets/5086849/2533672/48c59300-b564-11e3-897e-5c6033d9538f.png)