Merge pull request #193 from ddssff/master

Changes corresponding to ghc trac 8768
Merge pull request #195 from ddssff/master

Changes to make haddock happy
update boot configuration, improve some booter errors
correct with-config command line option
don't track changes to boot/shims/test cache archives
Update .travis.yml

Change --init to --dev
Fix typo
Merge pull request #197 from ddssff/master

Strip the copyDest from the path written into the wrapper script
support adding deps to group
support environments without a home dir
Require Cabal>=1.21 and relax lens dependency