Merge pull request #2 from nbr2/rearchitecture

Rearchitecture
Merge pull request #3 from nbr2/master

Sprite text labels
Merge pull request #4 from nbr2/master

selection handling
Merge pull request #5 from nbr2/master

more atom selection
Merge pull request #6 from nbr2/master

Shapes
Merge pull request #7 from nbr2/master

shapes
Merge pull request #8 from nbr2/master

more shapes
Merge pull request #9 from nbr2/master

volumetric data, voxels, transparency bug fix
Merge pull request #10 from nbr2/master

Separate Marching cube / isosurface generation
perform secondary structure analysis if there are now HELIX/SHEET records
this is necessary for pocketquery which doesn't store this info
Merge pull request #11 from nbr2/master

4GQB test data; fixed line/cross render bug