Doc: update KnownBugs and faq. (#2196)

1. Remove bug about unsupport systems, because we has pretty error msg.
2. Add usage for remote debugging.

Relate: #1883, #1829, #861, #1332.

Documentation/KnownBugs.md

 # Known Bugs
 
-- Delve does not currently support 32bit systems. This will usually manifest as a compiler error in `proc/disasm.go`. See [Issue #20](https://github.com/go-delve/delve/issues/20).
 - When Delve is compiled with versions of go prior to 1.7.0 it is not possible to set a breakpoint on a function in a remote package using the `Receiver.MethodName` syntax. See [Issue #528](https://github.com/go-delve/delve/issues/528).
 - When running Delve on binaries compiled with a version of go prior to 1.9.0 `locals` will print all local variables, including ones that are out of scope, the shadowed flag will be applied arbitrarily. If there are multiple variables defined with the same name in the current function `print` will not be able to select the correct one for the current line.
 - `reverse step` will not reverse step into functions called by deferred calls.

Documentation/faq.md

@@ -53,3 +53,26 @@ the terminal TTY.
 1. Assign the process its own TTY. This can be done on UNIX systems via the `--tty` flag for the 
 `dlv debug` and `dlv exec` commands. For the best experience, you should create your own PTY and 
 assign it as the TTY. This can be done via [ptyme](https://github.com/derekparker/ptyme).
+
+#### How can I use Delve for remote debugging?
+
+It is best not to use remote debugging on a public network. If you have to do this, we recommend using ssh tunnels or a vpn connection.  
+
+##### ```Example ``` 
+
+Remote server:
+```
+dlv exec --headless --listen localhost:4040 /path/to/executable
+```
+
+Local client:
+1. connect to the server and start a local port forward
+
+```
+ssh -NL 4040:localhost:4040 user@remote.ip
+```
+
+2. connect local port
+```
+dlv connect :4040
+```