file editing support changes
support check for dirty state during edit and close
Merge branch 'file-editing'

Conflicts:
	src/main/java/org/iplantc/de/client/viewer/commands/VizURLViewerCommand.java
	src/main/java/org/iplantc/de/client/viewer/presenter/FileViewerPresenter.java
	src/main/java/org/iplantc/de/client/views/windows/FileViewerWindow.java
core-5044 core-5045 allow users to create and edit files in DE