Use render targets in vview

Only mono rendering mode
Move serialization functions to namespace
Enable 64-bit socket parameters
Don't store socket in remote client
Re-enable VV_SERVER environment variable

This variable will be used if no server was specified otherwise
Remote renderers request an appropriate server
Disable all client state but vertex array for ibr

Segfaults occur if a client state is enabled but no buffer data
is provided on NVIDIA cards