Multi-threaded TMS packager.
Multi-threaded TMS packager improvements.
Merge branch 'master' of https://github.com/gwaldron/osgearth
Fix for build error.
Update DateTime.cpp

Without string.h memset is not declared
Merge pull request #357 from mucisk/patch-1

Update DateTime.cpp
Call osg::Program::releaseGLObjects from within VirtualProgram::releaseGLObjects
Merge pull request #358 from chrisstankevitz/releaseglobjects

Call osg::Program::releaseGLObjects from within VirtualProgram::releaseG...
TerrainLayer: added automatic cache invalidation based on TileSource last-modified-time; implemented for TMS only so far
Fix: TECHNIQUE_SCENE was not working becuase MP engine was not firing Terrain events for upsampled tiles
Fix: #363 tracks demo not working properly
Fix: Draping and Clamping techniques were using too much memory; had to set the camera's implicit render/resolve masks to zero to prevent OSG from automatically allocating unneeded buffers.
Merge branch 'master' into topic-incremental-update
Controls work