MERGE OpenMD development branch 1465:1781 into trunk
Various fixes for the RNEMD output.
Fixes to mdParser to handle vector assignments, fixes for VelocityVerletIntegrator deleting rnemd_ when it doesn't exist yet.
Tracking down a strange bug report. Fixing some output. Fixing some samples.
Cleaning up RNEMD log, adding XY area to Snapshot
Adding new RNEMD options and output file format
Code readability updates.
Refactored Snapshot and Stats to use the Accumulator classes. Collected a number of methods into Thermo that belonged there.
Reorganized source directories, added RNEMD and flucQ blocks for options parsing.