Support disabling server pausing for compute API

This adds a togglable compute feature for pause/unpause.

The Docker driver does not currently support this feature.

Change-Id: I6f5f1f4624e34801aa52def7450e65716073fc65
Support disabling suspend/resume for compute api

The suspend extension may not be available,
allow it to be disabled.

Change-Id: I6ec48d2903f817334ec94b0baa8ba223d2602d1f
Merge "Support disabling server pausing for compute API"
Merge "Support disabling suspend/resume for compute api"