Adding a "vint" type to Thrift

[Bryan Duxbury]

All,

We've been following the discussion on THRIFT-110. I think as a first  
step we should add a "vint" (variable integer) to Thrift.

My general proposal is that we add vint as a new type. Protocols that  
don't do variable length integers can treat vints as i64s. Protocols  
that do implement variable length integers can choose encodings that  
make sense for them.

We'd have to change the compiler and all the generators and libraries  
to recognize vint, if for no other reason than to treat it as an i64.  
However, this would make implementing other protocols that included  
variable length integers very easy.

Are there any objections to this proposal? If not, I'll make an  
issue, and Rapleaf is willing to commit time to this enhancement.

-Bryan