A fix to the build and the jump-to-definition feature. Fixes #544, fixes #633

Fixes #544, fixes #633
re: "switch to the code tab only if the procedure has been found", that's fine. `app.Tabs` can handle the event and react appropriately, switching tabs or not, as it chooses.

re: "I still need some way to pass the EditorColorizer to the function". why? isn't it enough for the event to contain the name that needs to be looked up? not sure I understand the problem here.

re: "should I make another event": one seems sufficient to me.