Enhance version to allow for compact style

This is backwards compatible (i.e. doesn't change the default behavior),
but allows devs to override to get this compact style.  The style chosen
is very simple - `foobar version 1.2.3`.  Doing stuff like the GNU
standard requires some metadata about licensing which I don't want to
get into.

That being said, one could customize the format via

```ruby
version MyAPP::VERSION, :compact => true
                        :format => "%s %s\nCopyright (c) 2013 Whoever\nLicensed under Apache license"
```

To achieve this on a per-app basis.
Make internals lazily created to allow flexibility

Closes #65

There's no real reason that `main` has to be where the internal
state of the module gets created.  So, lazily created the options
hash and option parser so that calling other DSL methods before main
will work.
Add 2.0 to travis builds
Bump version
added "-" trim mode for copy file to support -%> ERB closing syntax
converted to .ruby-version and .ruby-gemset over .rvmrc; fixed typo in test/test_exit_now.rb
initial addition of multilevel command feature
added command feature