Bug fixes for the editor tools:
- saved last selected editor tool so it can be retrieved after the fragment is recreated (i.e: after orientation switch). Before the selected tool would reset to the marker tool on orientation switch.
- exported commonly used code into functions.
- updated the editor tools view to reflect the selected tool after orientation switch.
- updated the editor activity to update the state of the tools on resume.
Bug fixes for the editor tools item detail window:
- updated editor activity so that reference to a displayed item detail window is retained across activity lifecycle events. Before that update, dismissing an item detail window after a lifecycle event (i.e: orientation switch) would leave the mission item in a selected state (instead of deselecting it), among other possible issues.

- updated the mission detail fragment to notify its listener/parent when it's being dismissed, when shown as a dialog.
Merge pull request #796 from ne0fhyk/fix_editor_tools

Fix editor tools bugs