draft proposal for ref counting in D

[Walter Bright]

If autoreleasepull is just a handy way to lump together Release() calls, then 
that is quite unnecessary if the compiler inserts calls to Release() 
automatically. If it is, instead, a promise that members of autoreleasepull do 
not leak references outside of that object, then this is very problematic for D 
to guarantee such - and guarantee it it must. I.e. it's "escape analysis" in 
another disguise.

I think the compiler should pick where to put the Release() calls, that is the 
whole point of ARC. If the compiler can do sufficient escape analysis to 
determine that the calls can be elided, so much the better.