old system (for example, the meaning of 'a') has yet to be restored. In the
new scheme, this will be done by definition a function outside of the value
expression logic, rather than the tight coupling between journal innards and
value expressions that occurred in 2.x.
double has been disabled, because I am no longer packaging the gdtoa library
with Ledger (because double conversion really has nothing to do with what
Ledger does). If you wish to use it, you can find gdtoa in cpp-rewrite-2006,
under a sub-directory of the same name.
