Pass the -j flag from 'buildAction' to 'installAddSourceDeps'.

Fixes #1272.
Print a message when installing add-source dependencies.
'cabal get': don't add the version number to the dir name when forking.

Fixes #1279.

Test:

$ cabal get binary
Downloading binary-0.7.0.1...
Unpacking to binary-0.7.0.1/

$ cabal get binary -s
git: clone "git://github.com/kolmodin/binary.git"
Cloning into 'binary'...
remote: Counting objects: 2912, done.
remote: Compressing objects: 100% (1383/1383), done.
remote: Total 2912 (delta 1184), reused 2868 (delta 1145)
Receiving objects: 100% (2912/2912), 571.62 KiB | 460 KiB/s, done.
Resolving deltas: 100% (1184/1184), done.
When repo fork fails, show the package version in the error message.
Update bootstrap.sh

Following the third comment here (of dafis)  http://stackoverflow.com/questions/16128503/trouble-with-installing-cabal-on-mac it seems that mtl-1.* should not be permitted by the regex on line 56, 

    MTL_VER="2.1.2";       MTL_VER_REGEXP="[12]\."     # == 1.* || == 2.*

since in fact mtl-1 is rejected by the build-depends in the cabal file, which mentions  

    mtl      >= 2.0      && < 3

But perhaps this is a wrong understanding.
Merge pull request #1283 from michaelt/master

mtl-1.* wrongly permitted by boostrap.sh?
Spelling.
reconfigure: be more verbose when run with -v.
Redundant imports.
Merge pull request #1277 from 23Skidoo/build-j

Add a '-j' flag to the 'build' command.
Merge pull request #1280 from 23Skidoo/cabal-get-dirname

'cabal get': don't add the version number to the dir name when forking.
Remove duplication between 'D.C.SrcDist' and 'D.S.SrcDist'.
Fix a bug in 'sdist --zip' that prevented it from working.
Merge pull request #1282 from 23Skidoo/sdist-remove-duplication

Remove duplication between 'D.C.SrcDist' and 'D.S.SrcDist'.
Mention 'hc-pkg' in 'sandox help'.
Formatting.
Add 'test -j' and 'bench -j' flags.
80-col violations.
Support for 'test -j' and 'bench -j' in cabal-install.
80-col violations.