Terminate var declarations with semicolons if outside for loop heads.

A while back I started adding semicolons at the end of all variable
declarations, but that wasn't quite right, as @spicyj discovered:
c8d313a1e265909d50a9191e6c64f2afd42d4a4e.

This commit should get both cases (for loops and otherwise) right.

Fixes #77.