Revert "Merge pull request #12 from autotest/provider-libs"

This reverts commit c6c5aa5719c1afd7d788b45b542c009cfb2c9590, reversing
changes made to 9ca076451044351e8c255465d33d0345f145993c.
Add guestfish_block_dev
Merge pull request #1 from shi2wei3/master

Sync upstream and add guestfish_block_dev