Add IDE support for watching app folders for file changes

[trevordevore]

When using an external editor like SublimeText to edit files in a Levure app that is open in the LiveCode IDE, the external editor is responsible for notifying Levure that a file has changed and that it should be reloaded in the IDE. Ideally the IDE would be watching for file changes and automatically reloading files that change. This would allow the developer to use any 3rd party editor to modify files while still keeping the IDE up to date with the latest changes.

fswatch may work if implemented as an IDE plugin. Ideally an LCB wrapper would exist around it but it should work with open process as well. Using the Levure app array, the plugin can determine all root folders that need to be watched. When a file within those folders is modified the plugin can check to see if it is loaded in the IDE. If it is then the file would be reloaded.