WIP: Split into shoes, shoes-dsl, shoes-swt
Clean out the shoes meta-gem
Add build:all task
Add install/release gem tasks for sub-gems
Move development dependencies to Gemfile

This removes duplication in our development dependencies. Let's see
if there are any downsides.
Merge from master
A bit of refactoring trying to get build:all to work.. didn't

* moved the generation of the  all tasks outside of the loop, as
  that caused it to be executed for each sub gem i.e. 3 times more
  than necessary.
* some minor stuff
* no idea why, but build:all only builds the shoes gem for me,
  tried different dependency declarations didn't change... but
  then again I'm not good at rake
Executables only at one place (dsl for now, might change)

* had to add the cli back in to the files path
Load swt backend in CLI (sets backend) amd add swt.rb to swt gem
Add lib/shoes/ui

Move UI-related classes into ui directory.
Move DSL-related requires into lib/shoes/dsl.
Move Nokogiri dependency to shoes gem
Add shoes-dsl as a dependency of shoes-swt
Remove extraneous gem task
Add manifests for gems
Rework gem task dependencies

It's too confusing and easy to get wrong when iterating over an
array of task types. Even though there's a small bit of repetition
in this version, it's much cleaner. And correct.
Only include Rakefile and app.yaml in shoes meta-gem
Cache file lists in manifests

Because we run test files twice. Also remove duplicate entries for
spec files in the shoes-dsl manifest.
Add manifests/common.rb to common manifest
Move Shoes constants to DSL
Merge master into gems

Note that the dependency on the Code Climate coverage reporter
has moved to the Gemfile, with the other development dependencies.
Conflicts:
	shoes.gemspec