Server version check

[rjahn]

We need a check for client/server compatibility...

similar to this one: sibvisions/reactUI#343

Best would be a server-side check. Client sends supported server version and server checks with own version!

[rjahn]

If you send the serverVersion to the server via startup request:

2.0.0 -> 3.0.0 -> Error
2.1.0 -> 2.0.0 -> Error

2.1.0 -> 2.1.1 -> OK
2.1.0 -> 2.2.0 -> OK
2.1.1 -> 2.1.0 -> OK (server has no relevant changes)

A major version change is not allowed.
A minor version change is allowed as long as server version is bigger.

If an error is detected, the server sends a new response:

name: badClient
info: text

e.g.

[ {
  "name" : "badClient",
  "info" : "UI is incompatible with server [1.0.0 ! 2.0.0]"
} ]

[rjahn]

Current server version is 2.1.0