(maint) Move local egrammar makefile tasks to main Rakefile
(PUP-3001) Revert future parser change removing dynamic scoped defaults

This reverts the change in PUP-867 by (again) calling the same 3x logic
for looking up defaults. The implementation of PUP-867 also added tests,
and one of those are now changed to reflect the changed behavior.
Merge pull request #2957 from hlindberg/PUP-3001_revert-867-dynamic-scoped-defaults-removal

(PUP-3001) Revert future parser change removing dynamic scoped defaults
Merge pull request #2943 from jpartlow/maint/master/move-egrammar-make-to-rake

(maint) Move local egrammar makefile tasks to main Rakefile