Polish a few things (#81)

* Implement/suppress various compiler/clippy lints

* Change `tool_init` to take `ToolType` by value

* Factor out error conversion into a function

* Consume parameters with `todo`

* Make `workspace` stuff public

Making them public also removes the warnings
without having to suppress them.

Also, this commit removes the unused import of
`EditorError`

* Remove allow(unused_variables), use vars in `todo`

Also implements `Debug` on `DocumentToolData`

core/editor/src/lib.rs

@@ -1,3 +1,6 @@
+// since our policy is tabs, we want to stop clippy from warning about that
+#![allow(clippy::tabs_in_doc_comments)]
+
 #[macro_use]
 mod macros;