Add vrpn_ConnectionPtr.h, a smart pointer for vrpn_Connection using existing reference counts.
Add ConnectionPtr to API to install.
Fix permissions.
Normalize build of PDI driver.
Add warning suppression to PDI driver.
Silence warning.
Disable overloaded-virtual warnings since they're mostly noise.
Type conversions to avoid compiler warnings.
Type casts to avoid compiler warnings.
Wrap all install calls in a check of VRPN_INSTALL, set by default except in subproject builds.