Bulk/Multi File Uploads capabilities

• Added: Bulk/Multi File upload
• Added: devices command to display a list of all connected NodeMCU Devices
• Added: noninteractive options to the mkfs command to disable user interaction (confirm dialog)
• Added: Global --silent mode to disable log/status messages - only errors and direct outputs are displayed
• Added: Apache ANT build script example (programmatic file upload)
• Added: PHP Usage example (programmatic usage of fsinfo command)
• Added: Python Usage example (programmatic usage of devices command)
• Added: Programmatic Usage Guide
• Added: Step-by-Step Getting-Start Guide to the Documentation
• Added: Output handler to the middleware (separate log, error, output handler are available)
• Changed: Cleaned up NodeMCU-Tool.js - a connection is now established within a helper function
• Changed: The Connector.upload function will not remove a existing file anymore - it's now handled by the middleware (eliminates code redundancy)
• Changed: The device-list is not shown anymore in case there is an error during the connection establishment - please use the devices command
• Changed: On error, the process will now exit with return-code 1
• Improved: Hex-Upload-Helper is only uploaded one-times during a connector session (speedup when uploading multiple files)
• Bugfix: Upload Errors were not forwarded to the frontend
• Bugfix: The --compile options doesn't check the file-type