[BuildTools] Problem with ASL and AC_CHECK_SIZEOF(long long)

[Lou Hafer]

Kipp,

	I did a bit of grepping, and it seems the problem lies in finding signed
and unsigned 64-bit data types to use in OSdtoa.cpp. You might want to have a
look at the set of tests in CoinUtils/configure.ac. They start by looking for
int64_t and uint64_t.

	dtoa looks like it started life as C code. That'd be another way to 
solve the problem: let it be C, instead of coercing it up to C++.

	The conclusion I take from this is that any C++ implementation that
cares enough to throw an error over `long long' defines int64_t / uint64_t as
alternatives.  Otherwise CoinUtils would fail to build on a regular basis.

						Lou