Add dependency on data-default-class to project templates.

 Here's the error I get without this fix to add a dependency on data-default-class in generate projects:

Linux: Ubuntu trusty (Ubuntu 14.04.1 LTS)

(yesod init for some project fooey)

    harold@omnom:~$ cd fooey && cabal install -j --enable-tests --max-backjumps=-1 --reorder-goals
    Resolving dependencies...
    Configuring fooey-0.0.0...
    Building fooey-0.0.0...
    Failed to install fooey-0.0.0
    Last 10 lines of the build log ( /home/harold/.cabal/logs/fooey-0.0.0.log ):
    $ loggerSet $ appLogger foundation}'
    In a stmt of a 'do' block:
    logWare <- mkRequestLogger
    (def
    {outputFormat = if development then
    Detailed True
    else
    Apache FromSocket,
    destination = RequestLogger.Logger
    $ loggerSet $ appLogger foundation})
    cabal: Error: some packages failed to install:
    fooey-0.0.0 failed during the building phase. The exception was:
    ExitFailure 1
    harold@omnom:~/fooey$