Fix the code that checks for the correct number of arguments

When we run the PHP script with no argument we get a notice about
attempting to access an undefined offset in an array.  The script
checks for the minimum number of arguments but that code is incorrect
because we need to count() the number of arguments.  This patch fixes
that code so that running the PHP script with no argument no longer
raises a notice and immediately ends the script, aborting with the
ERROR_MISSING_ARGUMENT exit code.

For more information see:

    https://github.com/ejmr/php-auto-yasnippets/pull/2#issuecomment-33948245
Add auto-complete source and setup function

This makes using the package easier for auto-complete users.

Signed-off-by: Eric James Michael Ritz <lobbyjones@gmail.com>
Add info on auto-completion to README.md

Signed-off-by: Eric James Michael Ritz <lobbyjones@gmail.com>
Merge branch 'github/pr/16'

* github/pr/16:
  Add info on auto-completion to README.md
  Add auto-complete source and setup function
Bump the version number to 2.2.0 and update the copyright year

The bump is for the auto-complete integration by Nate Eagleson.