updated code to match latest blockly version

updated from Spigot 1.8.8 to Spigot 1.9

- functionnal Blockly editor with initial scriptcraft Drone and inven…

…tory commands

- nanohttpd webserver serves Blockly files and save the javascript commands
- replaced scriptcraft readme with blocklycraft readme

Fix API generation

added new entities and spawn modules

removing bukkit-1.7.10 - replaced with spigotmc-1.8.8

Fix issue walterhiggins#261

fixes issue walterhiggins#254

version bump to 3.1.7

fixing fireworks problem on mac os