Add new option-list cell

This cell splices a list of values into the syntax checker command.
[Fix #174] Make load-path for emacs-lisp customizable
Make package initialization in emacs-lisp customizable
Add option to configure package-user-dir for emacs-lisp
Do not initialize packages by default
Update tests for emacs-lisp syntax checker

Add new tests for the effect of setting the new option variables.
Initialize packages automatically for user's configuration
Merge pull request #176 from lunaryorn/overhaul-emacs-lisp

Overhaul emacs lisp syntax checker