CrashReportingUI - Text in details text view can now be selected

- This is helpful should the HockeyApp API be down, having issues, and the user can't successfully report the crash.  The user would at least be able to copy/paste the crash log text into an email.
Merge pull request #15 from gcox/selectable-crash-log-text

CrashReportingUI - Text in details text view can now be selected