Make find_recipe() return specific recipe.

find_recipe() was just returning the first recipe from the set, not the one we
were looking for. It now checks the recipe_uri and tries to find the recipe
with specified id reverting to previous behaviour if failed to do so.
Parsing recipe_uri is not the best way to do this so in future we should
probably track the recipe_id somewhere inside the server.
restraintd: config_port memleak fix

Fixed config_port variable leak in server.c
Initial mh support for restraint client.

Support for multiple servers in the client, all recipes are now handled
separately(although in the same evloop). This does work with simple mh recipes
but error handling needs more work.
parse_new_job() wboard memleak fix

This commit fixes a wboard var memleak in parse_new_job() in case when hostname
is not specified.
Default wboard value for recipes with undefined wb.

Adding default whiteboard values for those recipes which have it undefined.