V8 javascript engine update, intermediate commit #1 (broken)
Fixed TMSPackager to use hasData instead of hasDataAtLOD to determine if subdivision needs to occur.
Merge branch 'master' of https://github.com/gwaldron/osgearth
Fix: add current node to lighting uniform helper consideration; change default overlay resolution ratio to 3.0
CMAKE: added git SHA to the osgEarth version readout
Merge branch 'master' of github.com:gwaldron/osgearth
Add AlphaEffect utility and add Control::setOpacity
Updated javascript plugin to work with the latest V8.
Merge branch 'master' of https://github.com/gwaldron/osgearth
Updated javascript plugin to work with the latest V8.
Merge branch 'topic-v8-update' of https://github.com/gwaldron/osgearth into topic-v8-update
Updated CMake files to work with the latest V8.
Line of sight fixes

Making sure _start and _end are valid in LinearLineOfSight before
calling compute.
Using a DPLineSegment intersector in Terrain::getHeight.
making sure makeAbsolute succeeds in GeoPoint::transformZ before calling
toWorld.
Update all HandleScopes to take an Isolate.
Changed terrainChanged for LOS to not create an extra group.

The extra group isn't necessary since the tile is already merged.
Removed all the background thread stuff from the los nodes

Since the onTileAdded callback is always going to execute in the update
callback we don't need to worry about if it's threadsafe to modify the
node.
Add stipple support to LineSymbol - issues still exist
Merge branch 'master' of github.com:gwaldron/osgearth
Added icu libs to V8 cmake setup.
Merge branch 'topic-v8-update'