Bump gocui

... and switch back from stefanhaller's tcell fork to the official tcell. This
basically reverts 7ccb871a45.

vendor/github.com/gdamore/tcell/v2/README-wasm.md

@@ -0,0 +1,61 @@
+# WASM for _Tcell_
+
+You can build _Tcell_ project into a webpage by compiling it slightly differently. This will result in a _Tcell_ project you can embed into another html page, or use as a standalone page.
+
+## Building your project
+
+WASM needs special build flags in order to work. You can build it by executing
+```sh
+GOOS=js GOARCH=wasm go build -o yourfile.wasm
+```
+
+## Additional files
+
+You also need 5 other files in the same directory as the wasm. Four (`tcell.html`, `tcell.js`, `termstyle.css`, and `beep.wav`) are provided in the `webfiles` directory. The last one, `wasm_exec.js`, can be copied from GOROOT into the current directory by executing
+```sh
+cp "$(go env GOROOT)/misc/wasm/wasm_exec.js" ./
+```
+
+In `tcell.js`, you also need to change the constant
+```js
+const wasmFilePath = "yourfile.wasm"
+```
+to the file you outputed to when building.
+
+## Displaying your project
+
+### Standalone
+
+You can see the project (with an white background around the terminal) by serving the directory. You can do this using any framework, including another golang project:
+
+```golang
+// server.go
+
+package main
+
+import (
+	"log"
+	"net/http"
+)
+
+func main() {
+	log.Fatal(http.ListenAndServe(":8080",
+		http.FileServer(http.Dir("/path/to/dir/to/serve")),
+	))
+}
+
+```
+
+To see the webpage with this example, you can type in `localhost:8080/tcell.html` into your browser while `server.go` is running.
+
+### Embedding
+It is recomended to use an iframe if you want to embed the app into a webpage:
+```html
+<iframe src="tcell.html" title="Tcell app"></iframe>
+```
+
+## Other considerations
+
+### Accessing files
+
+`io.Open(filename)` and other related functions for reading file systems do not work; use `http.Get(filename)` instead.