Removed Entity and Room.
Added two new interfaces: Entity and Exit (which extends Entity).
Restructured the package directory slightly.
Added new enum for exit types.
Started adding the code to build the UI.
Renamed DefaultPointer to SelectionTool, so updating references.
Added new button on the toolbar for the selection tool.
Added new enum for types of entity.
Paired back the Room code to the bare minimum for now.
Made changes for code clarity and reintroduced some code that had been moved up to CellPanel, even though it will mean a little bit of duplication of code.  Realised with a fresh pair of eyes that I was moving business logic back into the UI, even though it was only slightly.
Made changes for code clarity and reintroduced some code that had been moved up to CellPanel, even though it will mean a little bit of duplication of code.  Realised with a fresh pair of eyes that I was moving business logic back into the UI, even though it was only slightly.
Made changes for code clarity and reintroduced some code that had been moved up to CellPanel, even though it will mean a little bit of duplication of code.  Realised with a fresh pair of eyes that I was moving business logic back into the UI, even though it was only slightly.
Made changes for code clarity and reintroduced some code that had been moved up to CellPanel, even though it will mean a little bit of duplication of code.  Realised with a fresh pair of eyes that I was moving business logic back into the UI, even though it was only slightly.
Removed defunct tests.