Make toasterui to work in build mode

Hi,

This patchset is a preparation for the #7880 fix. As we're going to get rid of running bitbake server we need toasterui to work in build mode, i.e. with bitbake <target> -u toasterui.

If you want to test this functionality you can do the following:
- start Toaster
- kill bitbake server and observer processes
- unset BBSERVER
- add INHERIT+="toaster buildhistory" line to conf/local.conf
- run bitbake <target> -u toasterui

Expected outcome: you should see commandline build in UI without bitbake server
and observer running.

I've discovered nasty bug in handling setEventMask by bitbake server while working on this. It causes ignoring of the event mask set by toasterui. The result of this is that list of events in _ev_list variable is different from the actual list of events processed by toasterui. Here is the difference:
-bb.command.CommandExit
+bb.event.BuildCompleted
+bb.event.BuildStarted
+bb.event.ConfigParsed
+bb.event.DepTreeGenerated
-bb.runqueue.runQueueExitWait
+bb.event.RecipeParsed
+bb.event.SanityCheck
+bb.event.SanityCheckPassed
+bb.event.TreeDataPreparationCompleted +bb.event.TreeDataPreparationStarted +bb.runqueue.runQueueTaskCompleted
+bb.runqueue.runQueueTaskSkipped
+bb.runqueue.sceneQueueTaskCompleted

The fix for this bug is also included in this patchset.

Changes in v2: Added several missing events to the _ev_list.
Removed workaround code that ignores unwanted events.

Changes in v3: Fixed WARNING: Unknown event: <bb.event.BuildStarted object at 0x2554150>
Mentioned updating config in testing instructions

The following changes since commit f7f35a9d6ff43bd8cb75603557158617a80bb4e5:

toaster: cleanup of bin/toaster startup code (2016-03-01 12:35:38 +0000)

are available in the git repository at:

git://git.yoctoproject.org/poky-contrib ed/toaster/toasterui-in-build-mode
http://git.yoctoproject.org/cgit.cgi/poky-contrib/log/?h=ed/toaster/toasterui-in-build-mode

Ed Bartosh (7):
toasterui: reformat list of events
toasterui: update list of events
command: make setEventMask readonly
toasterui: check if setEventMask succeeded
toasterui: make toasterui to work in build mode
toasterui: exit on final events
toasterui: fix warning 'Unknown event'

 bitbake/lib/bb/command.py      |  1 +
 bitbake/lib/bb/ui/toasterui.py | 90 +++++++++++++++++++++++++++++-------------
 2 files changed, 64 insertions(+), 27 deletions(-)

--
Regards,
Ed