script: Support installing from a clean state
script: Support installing from a clean state

This adds a --clean flag to the install script which will do the
following before proceeding with the installation:

* prompt the user to confirm the clean
* stop flynn-host
* kill old containers
* destroy ZFS volumes
* remove Flynn files and directories

Signed-off-by: Lewis Marshall <748e1641a368164906d4a0c0e3965345453dcc93@lmars.net>

ozum/flynn,TribeMedia/flynn,rikur/flynn,TribeMedia/flynn,lmars/flynn,josephglanville/flynn,whouses/flynn,Brandywine2161/flynn,TribeMedia/flynn,shads196770/flynn,supermario/flynn,schatt/flynn,justintung/flynn,clifff/flynn,clifff/flynn,ozum/flynn,benbjohnson/flynn,josephglanville/flynn,supermario/flynn,flynn/flynn,felixrieseberg/flynn,GrimDerp/flynn,pkdevbox/flynn,lmars/flynn,technosophos/flynn,supermario/flynn,schatt/flynn,ozum/flynn,shads196770/flynn,philiplb/flynn,kgrz/flynn,benbjohnson/flynn,whouses/flynn,jzila/flynn,rikur/flynn,rikur/flynn,tonicbupt/flynn,benbjohnson/flynn,kgrz/flynn,flynn/flynn,whouses/flynn,kgrz/flynn,tonicbupt/flynn,technosophos/flynn,schatt/flynn,ozum/flynn,lmars/flynn,TribeMedia/flynn,benbjohnson/flynn,schatt/flynn,rikur/flynn,pkdevbox/flynn,felixrieseberg/flynn,pkdevbox/flynn,clifff/flynn,TribeMedia/flynn,supermario/flynn,arekkas/flynn,philiplb/flynn,tonicbupt/flynn,GrimDerp/flynn,TribeMedia/flynn,pkdevbox/flynn,technosophos/flynn,kgrz/flynn,Brandywine2161/flynn,arekkas/flynn,flynn/flynn,josephglanville/flynn,whouses/flynn,philiplb/flynn,shads196770/flynn,technosophos/flynn,kgrz/flynn,jzila/flynn,shads196770/flynn,kgrz/flynn,ozum/flynn,rikur/flynn,schatt/flynn,whouses/flynn,GrimDerp/flynn,Brandywine2161/flynn,Brandywine2161/flynn,GrimDerp/flynn,josephglanville/flynn,justintung/flynn,justintung/flynn,supermario/flynn,arekkas/flynn,jzila/flynn,lmars/flynn,GrimDerp/flynn,whouses/flynn,felixrieseberg/flynn,pkdevbox/flynn,benbjohnson/flynn,jzila/flynn,lmars/flynn,josephglanville/flynn,flynn/flynn,flynn/flynn,shads196770/flynn,rikur/flynn,schatt/flynn,justintung/flynn,GrimDerp/flynn,ozum/flynn,benbjohnson/flynn,philiplb/flynn,clifff/flynn,arekkas/flynn,tonicbupt/flynn,philiplb/flynn,supermario/flynn,tonicbupt/flynn,clifff/flynn,clifff/flynn,justintung/flynn,felixrieseberg/flynn,Brandywine2161/flynn,felixrieseberg/flynn,technosophos/flynn,josephglanville/flynn,justintung/flynn,arekkas/flynn,jzila/flynn,pkdevbox/flynn,shads196770/flynn,jzila/flynn,Brandywine2161/flynn