[atlaas] rename merge(cloud, raster) -> rasterize
[tools] clean pylab demo code
[cloud] from XYZ to XYZI, add intensity, 16B align
[export8u] rewrite export8u (debug only, use save for display)
[doc] update readme install info
[doc] add todos
[merge] replace if 5m closer

and use member variance_threshold instead of variance_mean
remove pseudo-persistent vertical info
[doc] add todo rename
[tool] fix robotpkg path
[doc] update doxyfile to 1.7.6.1
[test] add merge test
Bump to v0.1.4
[test] add assert_meta_xy slide test
[io] add empty dump/load point-cloud methods