fix to drift in usecTimestampNow() caused when computer sleeps
Merge pull request #3851 from ZappoMan/flightTimeDebugging

fix to drift in usecTimestampNow() caused when computer sleeps
Merge pull request #3847 from ey6es/metavoxels

Big metavoxel update: removed unused pieces, converted heightfields to "spanners" in order to allow arbitrary transforms, switched to 16 bit heightfields with lossless compression, some rendering improvements.
Merge branch 'master' of https://github.com/highfidelity/hifi into metavoxels
Catch and log BitstreamExceptions when reading datagrams.