5.5.0

Expect a blog post which goes in-depth. 

* kiss-chroot now sets saner defaults (-O2 instead of -Os). 
* kiss-reset has been removed.
* KISS_HOOK has been expanded to take a colon separated list of absolute file paths.
* A message now appears when a package has a repository hook but it is not executable.
* Added support for .tbz files.
* Made the default sha256 command use openssl (brings performance improvement).
* Variables are now supported in sources files.
* Added pre-update and post-update hooks.
* Build scripts are now given a tailored environment to reduce boilerplate.
* Fixed bug during package conflict resolution.
* Fixed non-atomicity during installation of packages causing system crashes.
* Optimized package installation (python3: old 7s, new 3.5s).
* Installation of packages is now a fail-able process (errors were ignored prior).
* The package manager will now tell you if any packages were dropped from repositories during updates.

NOTE: The swap to executing hooks is a breaking change. Hooks no longer have access to package manager internals and 
must keep their own state between invocations.

NOTE: All other changes are opt-in and there is no change in behavior if you do not make use of the features. 
This includes the tailored environment change and the variables in sources files.

NOTE: The variables in sources file change works for all but six packages in the official repositories. Of these six, half are related to 
using git tarballs (can be fixed), one is gzip/pigz (can be fixed), one has a date in its url (json-c) (can be fixed) and the last one is sqlite 
which uses its funky naming scheme.  It's a worthwhile change to unclutter commit history and ease maintenance.