Add user defined custom controls

• User can define custom inline styles, block styles and callback controls.

Fix minimum typings definitions version for 'draft-js'

Merge pull request #6 from niuware/development

Update draft-js types minimum required version

Add custom inline styes

• Add 'strikethrough' inline style
• Add 'highlight' inline style
• Fix a bug when setting an inline style with no input text

Add 'onChange' property

• Add 'onChange' component property
• Add default style name for theme override
• Update README file
• Update examples

Add 'Image' editor control

• Add basic image editor control
• Enable custom order for editor controls

First stable release

1.0.12

Update distribution file