#2132 - lint and fix with ale#command#Run

A new function is added here which will later be modified for public use
in linter and fixer callbacks. All linting and fixing now goes through
this new function, to prove that it works in all cases.

test/test_linting_updates_loclist.vader

@@ -64,6 +64,7 @@ Given foobar (Some JavaScript with problems):
 
 Execute(The loclist should be updated after linting is done):
   ALELint
+  call ale#test#FlushJobs()
 
   AssertEqual
   \ [