New functionality

• Support for gantt diagrams
• Yet more forgiving syntax for flow charts regarding spaces around links
• Default mermaid.css included as well as less structure for simple theming,
  • run gulp mermaid-less to create new less files
• default style for links is now possible

Issues closed:

• Issue #122 - Add a css file, mermaid.css, with default styling
• Issue #118 - Add capability for gantt diagrams
• Issue #108 - lower case v causes error in the parser
• Issue #67 - Label's css conflict with boostrap's .label