below commit uses POST_BUILD and PRE_BUILD to generate a fresh copy of
descriptor files for all OTB applications.
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] 3f7b6d40

This reverts commit b963a177.

BUG: #1567: fix compilation with GDAL 2.3.0

See merge request !79

Fix installation of GDAL bindings in standalone packages

See merge request !78

Resolve "wrong default RGB composition for Pleiades image"

See merge request !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 orfeotoolbox/otb!70

DOC: allow the configure step to print detected Qt5 version

See merge request orfeotoolbox/otb!76

Review: "add Wrapper/QGIS to generate qgis descriptors for processing plugin"

See merge request orfeotoolbox/otb!74

descriptors are generated with a custom target called
'generate_descriptors'. It depends on all OTBAPP.txt
So a missing .txt during installation will try to generate txt file.
This make sure all available applications have a valid descriptor.
There is a internal custom target called clean_descr which depends on
otbQgisDescriptor executable. This target re-create an empty directory
set in OTB_INSTALL_DESCR_DIR under OTB_BINARY_DIR. This make sure every
execution of generate_descriptor target is a clean one.

Finally, custom target is executed by make install using cmake's
install(CODE. Users can either can "make generate_descriptors" manually
or is automatically called during install.

New Itk modules

See merge request orfeotoolbox/otb!71

Packaging install fonts

See merge request orfeotoolbox/otb!67

COMP: missing parenthesis in packaging script

See merge request orfeotoolbox/otb!69

MRG: Merge branch '1554-add-wrapper-qgis-to-generate-qgis-descriptors-for-processing-plugin' into develop

MRG: Merge branch 'develop' into 1554-add-wrapper-qgis-to-generate-qgis-descriptors-for-processing-plugin