This patch is adding the configuration of the number of workers,
threads, and the size of the listen queue in Debian, which uses
uwsgi to run Heat API and api-metadata. Therefore, this patch adds
two new heat_api_uwsgi_config and heat_api_cfn_uwsgi_config
providers as well as two new heat::wsgi::uwsgi_api and
heat::wsgi::uwsgi_api_cfn classes.
Change-Id: I0e226046f6e2d69c89681948cee8e8830c186489