The Setup.hs script now queries darcs to create more detailed version info
to include in the startup message.
Note thought that with distributed version control systems like darcs,
the only way to uniquely identify a version is by the set of patches included.
Since the patches are not totally ordered, just looking at the last patch is
not enough.
For official releases, we tag the current set of patches so we can refer to
it by name (e.g. RELEASE-3.3.3).
The GF shell welcome message will now include something like
This is GF version 3.2.1-darcs.
Built on darwin/i386 with ghc-7.0, flags: interrupt
where a list of enabled configuration flags are included on the last line.
This is implemented in GF.Infra.BuildInfo by consulting the CPP macros
defined by the respective option in gf.cabal. For this to work,
GF.Infra.BuildInfo obviously has to be updated when new flags are added to
gf.cabal or if the CPP macros are renamed.
(Also, I suspect that if you reconfigure with different flags and rebuild GF
without cleaning first, the BuildInfo module will not be recompiled,
resulting in a misleading welcome message...)
