fix ghc-mod command
Merge pull request #189 from zakyggaps/fix-command-ghcmod

fix ghc-mod command issue #186
CabalInspector and ModuleInspector are cabalized and are
automatically built using cabal-install on a sandbox. This
means that the user no longer needs to install haskell-src-exts,
aeson and haddock (on the user db) beforehand, and that
SublimeHaskell won't break every time ghc is updated.
Removes dependencies from README.md
Depend on haddock-api instead of haddock
Don't use version-depending cabal-install options
Cabal: Improve haddock dependency.

Makes it work with both older and newer haddock and GHC.
More logging when compiling tools
Option "--disable-shared" breaks vector build on Mac OS X.
Configure cabal package before building.