Fixes indentation and tabs.

Uses style guide recommended by https://github.com/styleguide/ruby.
Merge branch 'style'
Removes support for dxf writting.
Merge branch 'write'
Minor gemspec style fix.
Fixes minor extra spaces.
Adds project scripts.
Merge branch 'scripts'
Cleans up dependencies.

Removes unneded dependencies and uses only gemspec statements.
Merge branch 'deps'
Adds support for extended attrs.
Adds support for text entity.
Adds support for color in entity.
Adds support for polyline.
Adds support for points.
Merge branch 'entities'