Fixes and improvements of "install" script. More in details.

* Version bump: 0.4.3
* Auto version management in install. Using fetching of remote version file if version wasn't specified.
* Fixed path to /SystemUsers/SoftwareData
* Improved cleanup after install. Remove useless FHS remains from /
* Disabled reloading of sysctls during installation.
* Added snapshots for more locations.
* Added changelog