Install trollop to crossfader gemset

Without this patch the `/opt/crossfader/bin/crossfader` executable fails
to start because it cannot load trollop.  This patch addresses the
problem by installing trollop into the crossfader runtime gemset at
`/opt/crossfader/runtime/gemsets/crossfader`.
Install base gemset for each config that has a gemfile

Without this patch gems are not automatically installed for each of the
Ruby runtimes that need certain gems installs.  In particular, each
runtime should at least start with `bundler` installed in the default
gemset named `crossfader`.

Users will be expected to install their own gems using something like:

    crossfader --gemset foo exec gem install bar --no-ri --no-rdoc