Remove pause feature.

- Wasn't being used very much.
- The background workers should only be using idle cpu, so shouldn't
  have any outward effect.
- Could also use less workers if necessary.

BUGS

@@ -1,8 +1,4 @@
 Current
-- Sometimes a paused worker has the running status (blue), when it should
-  have the paused status (yellow).
-- If a job is paused for longer than the timeout period, sometimes it has
-  the timed out status when un-paused.
 - Tmp files are being left behind after shutdown.
 - All tools in AppImages aren't working correctly. See ./vigil --self_test
 
@@ -256,6 +252,12 @@ Fixed
 - The brightness of the summary's title slightly changes when focused.
   <- Went away!
 - Timeout statuses aren't appearing. Probably related to subprocess.run.
+- Sometimes a paused worker has the running status (blue), when it should
+  have the paused status (yellow).
+  <- Dropped pause feature.
+- If a job is paused for longer than the timeout period, sometimes it has
+  the timed out status when un-paused.
+  <- Dropped pause feature.
 
 
 Won't fix