Fix 'deprecated' warning on focus selection

• Fix a deprecated warning shown when the focusing the editor selection.

Enable value reset

• The editor state is updated when the value property changes

Rewrite class as function component

• Rewrite the MUIRichTextEditor class as a function component
• Optimize rendering of EditorControls component
• Update usage of the ref property for external save trigger

Update 'draft-js' version

• Update 'draft-js' to version 0.11.1
• Update development dependencies
• Add width and height properties for the 'image' control
• Restyled the popover component when adding a 'link' or 'image'
• Hide inline toolbar when a popover is shown from the main toolbar

Refactor 'EditorControls' component

• Custom controls list is only updated when the customControls property changes
• Update unit tests

Add inline toolbar feature

• Add inline toolbar feature to display controls in a pop-up inside the editor
• Add 'toolbar' and 'inlineToolbar' flag properties for toolbars visibility
• Add toolbar class name for theme overriding

Add custom decorators feature

• Now user can define custom decorators for the editor
• Updated examples and documentation

Send the latest state object to 'onChange' property

Before the onChange property callback received an editor state object previous to the last update. This fix ensures the callback will receive the actual latest editor state.

Use TS 'noImplicitReturns' configuration by default

Merge pull request #10 from niuware/development

Use TS 'noImplicitReturns' configuration by default

Add controls and fixes

• Add 'undo' and 'redo' controls
• Prevent render repeated controls
• Fix a bug that focused incorrectly the editor when inserting a link