Break out the broom for some cleanup work

Break out the broom for some cleanup work

Maintain the MAINTAINERS file. Removed src/plugins/*.am listings. Added
a couple of plugins.

Add vlib_process_create (vlib_main_t *vm, char *name,
                         vlib_node_function_t *f, u32 log2_n_stack_bytes);
/** @brief Create a vlib process
 *  @param vm &vlib_global_main
 *  @param f the process node function
 *  @param log2_n_stack_bytes size of the process stack, defaults to 16K
 *  @return newly-create node index
 *  @warning call only on the main thread. Barrier sync required.
 */

This function makes it easy to spin up periodic processes when features
are enabled for the first time. That coding pattern is highly recommended.

Update the emacs-lisp plugin generator to use vlib_process_create,
instead of generating static periodic process nodes.

Change-Id: Icda33e93b9034779d3a3e228cd1110af14b058a5
Signed-off-by: Dave Barach <dave@barachs.net>