Introduce typed stack frames
Add STACK_FRAME_TYPE_PROMISE
Set current scope on bundle stack frame push
Add STACK_FRAME_TYPE_BODY
Push bundle stack frame in GatherPromisedMeasures
Do not set current scope "sys" in GenericAgentDiscoverContext.

There should not be a point where special variables are not set
explicitly.
Do not set current control_{agent_type} scope in GenericAgentDiscoverContext
Add acceptance test for match scope behavior
contrib/reindent.pl: add fix for older Emacsen without --chdir
Redmine#2178: add filestat() function and cfengine_stdlib.cf support