a bug is introduced in v2.0.2 defvar-local change.
the zero-input-full-width-p variable need to have a buffer local binding
when zero-input-mode is enabled. right away, not on first set.

- renamed zero.el back to zero-framework.el
- to build a dist, just run "make".
  the zero.el template is in zero.el.in
- zero.el is built and added to git repo in git pre-commit hook. it will
  be kept in master branch.
- fixed a few package-lint style warning.

- fix almost all checkdoc problems. the rest I don't know how to fix.
- add git pre-commit hook

so that user can bind any key to them.