Hardcoded magic numbers

Hello all again,

IMHO this is not clean to have magic limits inside the interpreter.
For example, we have 10 * 1024 * 1024 (maximum chunk size
to allocate) and 50 * 1024 * 1024 (maximum new size for reallocated
chunk), both in gc.c. It may be useful to set these limits from command
line or even from Ruby program like this:

GC.allocmax(50 * 1024 * 1024)
GC.reallocmax(128 * 1024 * 1024)

Also we can check (on UNIX at least) per-user limits (ulimit)
and set these values accordingly. Any ideas ?

Dmitry