Follow change in logic regarding bootcount when committing update.
Follow change in logic regarding bootcount when committing update.

We don't update the bootcount anymore when Mender commits an update,
because it's not necessary (it's not used as long as
"upgrade_available" is 0), so don't check for that. But add some
additional checks right after we have updated, but before rebooting,
to make sure the expected environment is there.

GregorioDiStefano/meta-mender,bboozzoo/meta-mender,GregorioDiStefano/meta-mender,bboozzoo/meta-mender,bboozzoo/meta-mender,GregorioDiStefano/meta-mender,bboozzoo/meta-mender