fix(lean-flycheck): make column optional when detecting error/messages

fix #194
fix(emacs/Makefile): add missing Makefile
fix(emacs/CMakeLists.txt): add all *.el files when install
feat(emacs/lean-company): add custom-variable lean-company-type-foreground

Close #190
fix(emacs/lean-company): import auto complete bug

fix #189
fix(emacs/lean-company): fix auto-complete behavior after tab

fix #192
fix(emacs/lean-mode): run company-lean--check-prefix before auto-complete

fix #191