Fix a theoretical config desynchronisation issue.

In rare cases, 'cabal.sandbox.config' and 'dist/setup-config' could
theoretically become desynchronised. Add a sanity check against this
possibility.
The package-db flag can now correctly handles relative paths
Fix BuildTestSuiteDetailedV09 on case-insensitive file systems

Fixes #1297 (again). Compiled object files are deleted before the detailed test
suite library is built. This is a workaround until the underlying cause is
known.
Merge pull request #1310 from ttuegel/test-build-detailed

Fix BuildTestSuiteDetailedV09 on case-insensitive file systems
Use a non-default build dir when building add-source deps.

Fixes #1281.
Merge pull request #1312 from 23Skidoo/sandbox-dist-builddir

Use a non-default build dir when building add-source deps.
80-col violations.
Use a subdir of 'dist' as build dir for building add-source deps.

Works better with 'cabal clean'.
80-col violations.
Make configAbsolutePaths work with sandboxes.

The package DB dir is created *after* we've changed the 'configPackageDBs'
setting with 'setPackageDB'.

Aside: we really need some functional tests for sandboxes.
cabal-install: put the Paths_cabal_install.hs and Paths_Cabal.hs in place as expected
disable hackage's preferred-versions (as we don't use it when merge ebuilds)

hackage.haskell.org/00-index.tar contains preferred-versions for some interesting
packages. For now it's 'base-3'.

Otherwise depends generated by hackport differ from ones pulled by ./Setup.hs.
cabal/cabal-install: renamed D.C.Exception -> D.C.ExceptionCI to avoid clash with Cabal's one

Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Fix error messages with "cabal update" -> "hackport update" Same fix as marty.rosenberg@gmail.com once did for cabal-install-0.8.2, which we now are replacing.
cabal/cabal-install: renamed D.C.Exception -> D.C.ExceptionCI to avoid clash with Cabal's one

Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
forbid cabal to check for self updates