``pfSense-upgrade`` should reinstall all packages on new version upgrades
Today pfSense rely only on pkg to detect what must or not be upgraded. Sometimes a package is rebuilt using the same version when a new pfSense version comes and it's not reinstalled during release upgrade and ended up being different from what is present on a fresh install.
In order to improve this situation and make sure all packages are the same if we upgrade or do a fresh install, implement a mechanism that forces all packages reinstallation when the value of /etc/version changes.
This way full reinstall will never happen while using a -DEVELOPMENT snapshot but will for sure happen when it moves to -ALPHA, -BETA, -RC or -RELEASE. Also will happen when upgrading from X.Y-RELEASE to W.Z-RELEASE.