[racket] 5.3.1 Performance

Racket 5.3.1 is amazing.

Compiled, it runs 20 update queries per second on a local SQL Server 
data store, whereas 5.3 ran, at best 5 queries per second. Both figures 
inclusive of garbage-collection. Also it is stable (5.2 and earlier had 
memory leaks, probably from mysterx library)

I don't have a basis for comparison, but running the web-server, I'm 
getting 300ms request-response cycles across the network, whereas I was 
seeing 900ms-1200ms cycles with v 5.3.

Numbers are with old development hardware and I haven't spent any time 
profiling the code.

Extremely, extremely impressive.

Thanks very much.

R./
Zack