Yaml frontend

[ilevyor]

People inexplicably like to write their DSLs in yaml, compile yaml down to grit

[stefanbeller]

create special refs for them.

What is the purpose of these special refs? (Are they in the superproject or in the submodule?)

[vi]

In the submodule, to automatically bring the non-forward submodule merge to superproject without touching any actual branches in the submodule.