feat: Abort immedietly when ^C is received. (#478)

Previously, we attempted to perform a clean shutdown, which could take a
significant period of time on slow filesystems. This commit changes the
shutdown logic to abort immedietly when ^C is received by the program.

src/progress.rs

@@ -79,7 +79,6 @@ pub struct RuntimeErrors {
     pub file_not_found: HashSet<String>,
     pub unknown_error: HashSet<String>,
     pub interrupted_error: i32,
-    pub abort: bool,
 }
 
 /* -------------------------------------------------------------------------- */