Added an Option for errors and messages, which use MessageBox to write to Output Window

WE has various cases of showing MessageBox for Information purposes (not YesNo boxes).

Sometimes, when user re-saves bundles too quick, the File System has file in lock and *bad things will happen*, causing MessageBox to show up. That's not necesseraly a bug, as writing some save-queue would require not appropriate to the problem time.

Still being on version 1.4.1 I have been experiencing the file not found errors for the js and css in bundles. I assume, that under normal conditions, when paths are specified fully and the Sharepoint Mapped Folders are not the case, everything will work as expected.
The bundle errors "path not found" appear sporadically, I was not able to debug the exact reason, as it is being used on a production project, however they are ALL FALSE POSITIVE.
Having N bundles with relative Sharepoint mapped paths causes each bundle to fail (first or last file not found error) causing in turn N MessageBoxes which in turn frustrate a programmer (he have to click his way through all of them), assuming the bundles are being recompiled every time onBuild and onSave.

So as an acceptable alternative we just implement an option to route MessageBox.Show to Output Window, so no user interaction would be necessary.

The option is defaulted to FALSE and have no affect on existing configuration until toggled.
When user toggles the options, he understands, that errors will go to the output and he have to check it periodically, so no harm in not showing a MB.

Regards,
 Max