Merge pull request #1 from michael-afanasiev/devel

Devel
added kdtree.h
Merge commit.
Working on monch, cleaned up a bit.
Added threshold value for 1d model interpolation.
Added topography interpolation.
Added crust interpolation.
Added the option to use a smoother.
This version created a great looking interpolation of europe. Benchmark.
Produced Korbinians update.
Distance search for kernel works.
Generated first kernel. Sent a picture to caroline of it.
Added connectivity list generation.
Fast extract, smoother seems to work. Can begin cleanup.
started cleanup. monch old-model-test.
Moved back to serial netcdf write. Instabilities.
Daily commit. Broadcasts arrays for kernel smoothing, also the box constrained search may be working.
Cross-processor kernel smoothing works well enough
Good. Milestone. Generated a "perfect" specfem3dGlobe mesh on 150 cores. Hell yeah.
Generated 3 successive models for Korbinian.