BUG: fix issue #1639 Update UserValue flag in QtWidgetParameterList

Closes #1639

See merge request !142

ENH: display parameter description as tool tip for the QtWidgetBoolParameter

See merge request !149

Resolve "Warn otbcli user about unused parameters"

See merge request !144

REFAC: include-what-you-use in Modules/Core/

See merge request !138

DOC: Minor fixes in Software Guide

See merge request !140

BUG: fix issue !1639 Update UserValue flag when a parameter is modified in QtWidgetParameterList widget

The QtWidgetParameterList widget should signal that an input parameter as been
modify by the user.Then, it set the UserValue flag from the corresponding parameter to
True.
It was spotted as the UserValue flag is used by the ParseApplication method used
to list parameter modified by the user in the GUI which is used to build the
corresponding command-line from the application GUI (displayed in the Log tab).

COMP: fix gcc 7 'defined' warnings

See merge request orfeotoolbox/otb!127

DOC: Set of proposed edits to the documentation

See merge request orfeotoolbox/otb!137

C++14: Replace comments by '= delete'

See merge request !133

BUG: Fix missing QWidget parents

See merge request !125

Conflicts:
	Modules/Wrappers/QtWidget/include/otbWrapperQtWidgetBoolParameter.h

C++14: Replace ITK_OVERRIDE by override

See merge request orfeotoolbox/otb!131

C++14: Replace ITK_NULLPTR by nullptr

See merge request !130

Update screenshots in Monteverdi Cookbook section with wrong RGB color composition

Closes #1627

See merge request !129

BUG: Remove workaround for QT bug 22829

See merge request !126

Document third party environment variables

See merge request !124

DOC: add checklist to MR template

See merge request !136

New custom widgets for Float and Int parameters

See merge request !123

ENH: Add comments to MR template

See merge request !132