Add DragonFly as a known OS to Cabal
Merge pull request #1669 from markuspf/master

Add DragonFly as a known OS to Cabal
Use -prof packages on the Travis build bot.
TemplateHaskell/dynamic is still failing on Travis...
Also test with GHC 7.8.1 RC.
Put quotes around program names in some error messages

One user reported being rather confused by the message:

  cabal: The program happy version >=1.18.5 is required but it could
  not be found.

I guess they must have been wondering what a happy version was. They
said that this is much clearer:

  cabal: The program 'happy' version >=1.18.5 is required but it could
  not be found.

So that's what we now do.
check linker, other script fixups
Merge pull request #1673 from pullreq/bootstrap-script-update

check linker, other script fixups
Small 'bootstrap.sh' fix.
bootstrap.sh: fix CC detection

There were three errors in CC detection:

1. The wrong variable was used in the for loop.

2. The selected CC was checked for existence and execute perm,
   but instead of the full path to the executable just the basename
   was passed to test -x.

3. The info log message accidentally printed the value of CC.
bootstrap.sh: fix tar reading from stdin
Merge pull request #1674 from tuncer/fix-bootstrap.sh

Fix bootstrap.sh
'bootstrap.sh': disable curl's resume feature for now.

Hackage 2 doesn't support byte ranges at the moment, which makes curl exit with
error if there's an incomplete tarball present. Fixes #1675.