vm state and task state management

partially implements bp task-management
fixes bug 997867

also see http://wiki.openstack.org/VMState

Refactored the following API/state:
* rebuild
* migrate
* resize
* start
* stop
* delete
* soft delete
* rework sync_power_state in compute/manager.

fix broken tests, add transition diagram in dot

Change-Id: I3c5a97508a6dad7175fba12828bd3fa6ef1e50ee

doc/source/devref/vmstates.rst

@@ -8,6 +8,143 @@ Preconditions for commands
 The following diagrams show the required virtual machine (VM) states and
 task states for various commands issued by the user:
 
+.. graphviz::
+
+  digraph states {
+    node [fontsize=10 fontname="Monospace"]
+    /* states */
+    building [label="BUILDING"]
+
+    active [label="ACTIVE"]
+    paused [label="PAUSED"]
+    suspended [label="SUSPENDED"]
+    stopped [label="STOPPED"]
+    rescued [label="RESCUED"]
+    resized [label="RESIZED"]
+    soft_deleted [label="SOFT_DELETED"]
+    deleted [label="DELETED"]
+    error [label="ERROR"]
+        
+    /* apis */
+    create [shape="rectangle"]
+    create -> active
+    create -> error
+    building -> create
+
+    delete [shape="rectangle"]
+    delete -> deleted
+    building -> delete
+    paused -> delete
+    suspended -> delete
+    stopped -> delete
+    rescued -> delete
+    soft_deleted -> delete
+    error -> delete
+
+    soft_delete [shape="rectangle"]
+    soft_delete -> soft_deleted
+    soft_delete -> error
+    active -> soft_delete
+    stopped -> soft_delete
+
+    restore [shape="rectangle"]
+    restore -> active
+    restore -> error
+    soft_deleted -> restore
+
+    pause [shape="rectangle"]
+    pause -> paused
+    pause -> error
+    active -> pause
+
+    unpause [shape="rectangle"]
+    unpause -> active
+    unpause -> error
+    paused -> unpause
+
+    suspend [shape="rectangle"]
+    suspend -> suspended
+    suspend -> error
+    active -> suspend
+
+    resume [shape="rectangle"]
+    resume -> active
+    resume -> error
+    suspended -> resume
+
+    start [shape="rectangle"]
+    start -> active
+    start -> error
+    stopped -> start
+
+    stop [shape="rectangle"]
+    stop -> stopped
+    stop -> error
+    active -> stop
+
+    rescue [shape="rectangle"]
+    rescue -> rescued
+    rescue -> error
+    active -> rescue
+    stopped -> rescue
+
+    unrescue [shape="rectangle"]
+    unrescue -> active
+    rescued -> unrescue
+
+    resize [shape="rectangle"]
+    resize -> resized
+    resize -> error
+    active -> resize
+    stopped -> resize
+
+    confirm_resize [shape="rectangle"]
+    confirm_resize -> active
+    confirm_resize -> error
+    resized -> confirm_resize
+    confirm_resize [shape="rectangle"]
+
+    revert_resize -> active
+    revert_resize -> error
+    resized -> revert_resize
+
+    snapshot [shape="rectangle"]
+    snapshot -> active
+    snapshot -> stopped
+    snapshot -> error
+    active -> snapshot
+    stopped -> snapshot
+
+    backup [shape="rectangle"]
+    backup -> active
+    backup -> stopped
+    backup -> error
+    active -> backup
+    stopped -> backup
+
+    rebuild [shape="rectangle"]
+    rebuild -> active
+    rebuild -> error
+    active -> rebuild
+    stopped -> rebuild
+
+    set_admin_password [shape="rectangle"]
+    set_admin_password -> active
+    set_admin_password -> error
+    active -> set_admin_password
+
+    reboot [shape="rectangle"]
+    reboot -> active
+    reboot -> error
+    active -> reboot
+    stopped -> reboot
+    rescued -> reboot
+
+    live_migrate [shape="rectangle"]
+    live_migrate -> active
+    live_migrate -> error
+    active -> live_migrate
+  }
 
 .. image:: /images/PowerStates1.png