filterConfigureFlags: s/1.17/1.18/.

Some people have old snapshots of 1.17 installed, which causes build failures.
Warnings.
Make 'delete-source' point the user to 'sandbox hc-pkg'.

See #1447.
Tweak a message.
Improve the message printed by 'sandbox init'.
Create a package DB for the default compiler in 'sandbox init'.

Fixes #1450.
Added known extensions: OverloadedLists, EmptyCase, AutoDeriveTypeable, NegativeLiterals, NumDecimals, NullaryTypeClasses
Make the test suite build on GHC 7.2.
Fix test suite failures on Windows.
Warning on older GHCs.
GHC 7.4 warnings.
Merge pull request #1453 from patrick-premont/Issue1412

Added known extensions: OverloadedLists, EmptyCase, AutoDeriveTypeable, ...
Merge remote-tracking branch 'upstream/master'
Build selected test suites and benchmarks only

Issue #1451. Passes the extra arguments to 'cabal test' or 'cabal bench'
to the build phase so that only the requested test suites or benchmarks
are built.
Merge pull request #1456 from ttuegel/build-tests-selectively

Build selected test suites and benchmarks only
Add basic sandbox documentation
Test suite: canonicalize binary path before execution (haskell/cabal#1458)
Revert "Add basic sandbox documentation"

This reverts commit 6bfb5a200c2202baa313903c95ced835316b23aa.

The sandbox feature is already documented (see #1430).
Additionally, the documentation added in this commit is misleading:
'runhaskell Setup.hs sandbox CMD' doesn't work.
Update bootstrap.sh.
Merge pull request #1459 from Blaisorblade/topic/testsuite-failures

Test suite: canonicalize binary path before execution