context_pmc3 branch and backward compatibility.

[Vasily Chekalkin]

Hello.

In context_pmc3 branch I converted direct using of Parrot_Context* to 
Context PMC. Unfortunately it will break any HLL which depend on current 
Parrot_Context struct.

So, question is "Does deprecation policy cover this situation and we 
have to live with refcounted Context which causes memory leaks, 
segfaults and eat kittens for breakfast until next deprecation cycle"?


BTW, there is only 2 tests failing in parrot's testsuite. And after 
tweaking rakudo's sources it passing make spectest.

Ah. And yes, branch is ready for code review.

-- 
Bacek