Fix iteration on empty RB tree, add test
Fix parser test that checks for invalid promise type
Make sure function 'and' gets a caller promise, add acceptance test

Close #3173
Do not exit from loop in ExpandScalar if parts of it is still expandable

Close #3144
To policy-output-format=json, add line info to elements, remove absolute offsets
Merge pull request #835 from vohi/fix_3191

Log message about missing input files only verbose if ignore_missing_inputs is set
Include source path information in JSON output for bodies.