Replace cocoahttpserver with Swifter or GCDWebServer

https://github.com/httpswift/swifter https://github.com/swisspol/GCDWebServer Last commits to Cocoahttp are 3 years old and it's buggy. Swifter or GCDWebServer are maintained

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information