Have make uninstall remove .elc from installation path
Kill pending errors that are edited by the user

(Manual merge of a commit on master).
Fix scoping mistake (and reformat)

Found by byte-compiler, please pay attention to the warnings.
Remove errors that overlap completion targets
Add ocamlbuild leftovers to .gitignore
Merge pull request #211 from gsg/ocaml-402

Contributed by ggole, fix a bunch of minor stuff.