Keycloak-httpd-client-install

* fix bug with default ports 80 and 443
default ports should not be present in URL
* add utility get_entity_id_from_metadata()
* add get_server_info() REST query

* add methods to add/remove client redirect URI
* add function to parse SP metadata to extract
AssertionConsumerServiceURL's
* Add all AssertionConsumerServiceURL's as redirect URI's during
client registration.

* add --mellon-https-port option
* add --mellon-root option
* add --mellon-endpoint option
* add --mellon-idp-attr-name option
* remove --mellon-endpoint-path option, instead compute from other options
* allow admin password to be piped into stdin or via
KEYCLOAK_ADMIN_PASSWORD environment varialble
* fix template-dir default
* remove doc/keycloak-httpd-client-install.md, use man page instead
* add port to mellon-http-url and entity id
* add support for creating a client group mapper
* keycloak-httpd-client-install now adds group mapper
* add MellonIdP attribute to mellon_httpd.conf
* Add keycloak-httpd-client-install.8 man page

* Add keycloak-httpd-client-install.8 man page

* Initial version