Add golang plugin
* Handle *.go files * Runs `go build` in the project root * Needs GOROOT & GOPATH to be set in project env variables * Display go version in SDK section * Add project-tree build & rebuild enable support with callback functions
* Handle *.go files * Runs `go build` in the project root * Needs GOROOT & GOPATH to be set in project env variables * Display go version in SDK section * Add project-tree build & rebuild enable support with callback functions