Cookbook fixes for release 6.6

See merge request !96

BUG: #1580: update tag for FFSforGMM

See merge request !95

BUG: post_build on windows appends all commands

See merge request !91

BUG: change ParameterFile ext to None

See merge request !94

Fix itk packaging

See merge request !83

Solve empty default value doc

See merge request !88

BUG: error generating qgis descriptors

See merge request !87

below commit uses POST_BUILD and PRE_BUILD to generate a fresh copy of
descriptor files for all OTB applications.
orfeotoolbox/otb@b963a177

This has broken dashboard due to a dependency issue.
https://dash.orfeo-toolbox.org/buildSummary.php?buildid=318175

otbQgisDescriptor is not dependent on any otb applications and it is
TRUE. But it has a run-time dependency to all otb applications when we
auto-generating all depscriptors. This situation forces us to add a
dependency so that POST, PRE building targets works. These are only
executed if otbQgisDescriptor target is rebuilt hence, it is not run
everytime with make.

Revert of the initial commit[2] is to get source tree in to a stage which
was reviewed. The first version of post,pre build was pushed directly to
release rather than via MR. Current state in release-6.6 will result in
broken dashboard.

[2] orfeotoolbox/otb@3f7b6d40

PKG: disable dl test for python wrappings (GDAL)

See merge request !85

PKG: small exception for check on /usr path with libdrm

See merge request !84

Resolve "Error during OTB SuperBuild compilation on Ubuntu 16.04"

See merge request !82

This reverts commit b963a177.

BUG: #1567: fix compilation with GDAL 2.3.0

See merge request orfeotoolbox/otb!79

Fix installation of GDAL bindings in standalone packages

See merge request orfeotoolbox/otb!78

Resolve "wrong default RGB composition for Pleiades image"

See merge request orfeotoolbox/otb!73

Use OGRSpatialReference class to compare projref

See merge request orfeotoolbox/otb!65

Add new contributors and refer to CONTRBUTING.md in the SG

See merge request !60

Resolve : Application can't be launch through monteverdi

See merge request !70

DOC: allow the configure step to print detected Qt5 version

See merge request orfeotoolbox/otb!76