Be more friendly to package.el

Make the interactive commands for autoloading to let package.el load the load the package lazily on first use.

Do not implicitly rebind C-x o to comply with the [Emacs Lisp Coding Conventions](http://www.gnu.org/software/emacs/manual/html_node/elisp/Coding-Conventions.html#Coding-Conventions) which advises against changing the global state by merely loading a package, and to let the user “escape” the package if it was installed unintentionally.