Fix heronrc/heron parser

[objmagic]

Heron RC parser introduced by #1119 is full of design and implementation flaw and confusion, even after my dozens of comments. It could be a good PR if I close the original PR and rewrite one completely. Even fixing this parser feels like patching an already sinking ship.

Bug 1: #1257, which has been fixed. But my last comment is still not answered.

Bug 2: some obviously invalid patterns are not rejected. For example, heron now accepts arbitrary number of parameters after action (subcommand).

Since I am back working on cli tool again, I might find some time to clean up this tech debt.

[objmagic]

@kramasamy any comment on this issue?

[objmagic]

although it is hard to work on/maintain heronrc parser, it works alright. let's delay this issue...