Previously we said a package graph was inconsistent if two
dependencies on the same package name specified different
versions. Now we say that two such dependencies on different
versions are ok if there is a direct dependency between those
two package versions. So if your package graph ends up with
both base 3 and base 4 in it, then that's ok because base 3
directly depends on base 4, so we declare it not to be an
inconsistency. This removes the scary warnings at configure
time (fixing ticket #366) and also adjusts the invariant and
assertion of the InstallPlan ADT in cabal-install.

Ticket #323

We can still add more as necessary

Ticket #58. Does not yet include checking.

Allow flags, lib and exes in any order and handle unknown sections better.

eg "cabal -v configure" to mean "cabal configure -v"
For flags that are not recognised as global flags,
pass them on to the sub-command.

6.10.x was giving us 601 rather than 610.

Old aliases kept for compatibility

Ready to make the 1.6 branch

GHC < 6.10 put "$topdir/include/mingw" in rts's installDirs. This
breaks when you want to use a different gcc, so we need to filter
it out.

We need to tell the gcc bundled with GHC on Windows where its mingw
include directory is

ie preserves any existing user-supplied path and args

This is like openBinaryTempFile except it doesn't mark the permissions
with 600. This means datafailes get the right permissions when they are
installed.

This should really be in the base package.

Now it matches Control.Exception's type

This time it should work on linux too! But more significantly
it should work when the user specifies a particular gcc. It
would be very bad if the user gave an alternative gcc but we
still gave it -B for the lib files of ghc's gcc. This go is
rather cleaner as it uses the new program post-conf system.

The post-conf action gets given the configured program and is
allowed to do more IO and can add any extra required program
args. Should make it easier to do the gcc -B thing or ld -x

Needs cpp pragma as it has to work with just ghc --make
Did I ever mention I that hate cpp and compat modules?

Convert any '-' in the package name to '_' when generating the
path env var as most shells do not allow '-' in env var names.

This needs a bit of a kludge, as the vanilla way doesn't really exist
as far as the build system is concerned. It's just the absence of way.