Fix for "Sublime Text 3.app" not existing

use mm_app_location = self.get_plugin_client_setting('mm_app_location')
instead of hard coding
Fix for select -> selected for metadata
Hide alerts when loading

add call to $(".alert-message").hide(); for showLoading()
Metadata updates

* Expand standard objects in CustomObjects to CustomFields
* Properly select fields based on CustomObject and CustomField members
* Remove unused methods
* optimize loops