Add support for tracking and counting entitlements

Adds a plugin, entitle, to register to the entitlement server, consume
entitlements and to count and track them. It is also possible to
import an entitlement certificate (if for example the remote entitlement
server is unaviailable).

This uses the candlepin server from https://fedorahosted.org/candlepin/wiki
for entitlements.

Add a cron job to validate the entitlement status and syslog the results.

tickets 28, 79, 278

ipa-compliance.cron

@@ -0,0 +1,5 @@
+SHELL=/bin/bash
+PATH=/sbin:/bin:/usr/sbin:/usr/bin
+MAILTO=root
+HOME=/
+0 0-23/4 * * * root /usr/sbin/ipa-compliance