fixes #426 expose BMC information in foreman UI

Signed-off-by: Ohad Levy <ohadlevy@gmail.com>

This patch also adds an abstracted power management class for both VM
and BM

fixes #1947 - wrong notice pressing the power on/off button for vmware hosts

• now using the real state from the server
• also made sure that we validate power on/off requests
• ensured our fog server objects respond to to_s and to state

fixes #1667 - restrcutre fog extensions code