[cmake] get rid of GNUInstallDirs

was installing libs to <lib/x86_64-linux-gnu/> on Ubuntu 14.04
[tools] update matplot hist semilogy

using `semilogy` was not showing bars, while `hist(log=1)` is.
[tools] use figure method for figure setup
[export8u] compute real min/max from data
[merge] dont merge if diff(dist) > T
add export_zmean for postprocess (color video)
add tool to convert zmean w/cmap (aka. LUT)
[tools] inc cmap default quality
[tools] cleanup sampling method
[tools] dem keep original values

and set -10000 as nodata
and install atlaas_dem
[tools] cmap w/atlaas support (band names)

filter empty cells
[pcl] voxelgrid filter
[python] add cython+numpy bindings

for testing purposes, not meant for robots
[common] add stl display helpers
[python] cleanup cython
[python] wip using morse patch
[ci] fix gdal apt package ssl conflict

fix another dependency conflict with GnuTLS/OpenSSL ...

force install libgdal1h to replace:
libcurl4-openssl-dev by libcurl3-gnutls + libcurl4-gnutls-dev
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=759214

all those pkg should depend on |libcurl-dev !
[cmake] add option to build with PCL
[atlaas] merge skip empty cloud
[python] display merge stats