V1 - Autocomplete suggestions in editor

[preetham]

These series of commits implement text autocomplete feature in Dev-App.

• The editor now provides live autocomplete suggestions based on nodetypes as well as text typed in the editor.
• This is achieved by using "ext-language_tools.js", library provided by Ace.
• Autocomplete suggestions are based on snippets generated from nodetypes.
• Snippets are generated by "syntax_gen.js".
• generateNodetypes() runs at startup of server to generate snippets before user types.