Correct macro spelling to fix Linux build
Switch to Boost 1.48 by default for Linux, as websocketpp needs it.
Also turn on INSTALL_BINARIES_ONLY build flag as otherwise the build fails
at configure stage
Merge pull request #746 from playsign/ubuntu-fixes

Ubuntu fixes
Use VLE encoding for entity & component id's for web clients (same as native clients' protocol)
Handle scene modification messages from the client.
Process incoming websocket events immediately instead of using a update rate (SyncManager still has its own update rate.)
Fix world -> local calculation with parented rigidbody. Closes #747.
Move registering WebSocketServerModule script types to WebSocketServer class so that the function is called for each script engine.
Do not busy poll the WebSocketServer.
SyncManager & UserConnection refactoring. Make SyncManager independent of kNet messages. Add generic message send & receive functionality to UserConnection class (can be subclassed.) Make AssetModule use the UserConnection's send functionality instead of kNet directly.
Added the concept of protocol version, which is negotiated to the lowest supported by both client and server. Client/Server/SyncManager refactoring.
Initial unification of the UserConnection & SyncManager. WebSocketSyncManager removed.
Fixed null pointer access in AssetModule with WebSocket connections.
Fixed WebSocket connection type & transform sync threshold handling.
Change UserConnection's properties to a QVariantMap.
Store both XML & JSON data for UserConnectedResponseData.
Store the server port as a numeric value in the login properties instead of a string.
Refactor the way Websocket network messages are signaled. Signal every WebSocket message also globally from the Server. Do not signal unauthenticated WebSocket user messages.
Create subclass for kNet-based user connections. Change ConnectionType property in UserConnection to QString.
Fix compile error on Linux.
Rename kNetUserConnection -> KNetUserConnection.
Use explicit toBool() when checking user authentication status. Removed unnecessary code.