Don't allow 'sandbox-config-file' in '~/.cabal/config'.
Reconfigure if 'cabal.config' was changed.

Fixes #1485.
Add a FIXME.
Add a workaround for issue #1463.
Reconfigure on modified 'cabal.config' even when there's no sandbox.

See #1485.
Depend on Cabal 1.18 instead of 1.17.

Avoids potential conflicts with old Cabal snapshots.
Change an error message.

See #1488.
Merge pull request #1469 from 23Skidoo/issue-1463

Add a workaround for issue #1463.
Initialise 'configInstallDirs' properly when loading sandbox config.

Fixes #1482.
Bump version number of cabal-install to 1.18.0.1
Catch exceptions in findUsableBranchers

In the version of process that comes with GHC 7.7,
readProcessWithExitCode raises an exception when
the process could not be started (for example if
the command to be run doesn't exist).
Eliminate a warning in Distribution.Client.Get

System.Cmd has simply reexported rawSystem from System.Process
since at least process-1.0.1.1, the minimum version we allow,
and has been deprecated just as long :)
Merge pull request #1491 from rwbarton/rwbarton-get-s

"cabal get --source-repository" fails under ghc 7.7 when a brancher is missing
Merge pull request #1492 from rwbarton/rwbarton-warning

Eliminate a warning in Distribution.Client.Get
Unbreak the build on GHC <= 7.4.

Fixes #1494.
Merge remote-tracking branch 'upstream/master'
Fix AMP warnings
Merge pull request #1495 from thoughtpolice/amp-fix

Fix AMP warnings
Comment.
'cabal sdist': don't create a default Setup.hs in current dir.

See discussion in #1353.