sometimes after GetCandidate dbus call, zero-input-fetch-size and
zero-input-candidates is not updated. This was because the async
function callback didn't update the metadata in some places.

- update initial fetch size and fetch size to be 1+ candidates needed for
  target page.
- removed zero-input-build-candidates-complete function,
  each async call should have its own callback function, don't reuse this one.
  in callback function, post GetCandidate metadata should be updated.

since this is a backward incompatible change, I set version to v2.0.0.
all symbols and functions is now prefixed with zero-input.

This change is suggested by melpa reviewer.

- 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.

split ert tests to separate files. These tests are not required in melpa
distribution.

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

- merge lexical-binding line with file intro line
- allow capitalize zero in some docstring/error msg
- add "make pkg" this will create tar for package.el

according to http://www.apache.org/legal/src-headers.html#headers, there
should be no copyright notice in the header.

added "make compile" to byte-compile and run tests in emacs batch mode.

- added zero-version variable in zero-framework.el

dbus based sync and async api both works.
- added error handler for dbus client in emacs lisp.
- use lexical-binding for all files
- added M-x zero-reload-all this will byte compile and reload file files.