bitbake: cooker/cookerdata/utils: Improve context management

The current execution context management for bitbake is ugly and the
use of a global variable is nasty. Fixing that is hard, however we
can improve things to start to establish an API for accessing
and changing that context.

This patch also adds in an explicit reset of the context when we reparse
the configuration data which starts to improve the lifecycle of the data
in setups like hob.

(Bitbake rev: 6c3281a140125337fc75783973485e16785d05a1)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/cookerdata.py

@@ -173,6 +173,7 @@ class CookerDataBuilder(object):
         self.postfiles = params.postfile
         self.tracking = params.tracking
 
+        bb.utils.set_context(bb.utils.clean_context())
         self.data = bb.data.init()
         if self.tracking:
             self.data.enableTracking()