This module sets individual flags for each feature; there is not one
"CXX11Features_FOUND" flags which is set. Thus, when putting the
module as REQUIRED, the only consequence is that we cannot disable
searching for it.
Instead, we make it optional, meaning that the flags won't get set if
it isn't included and the dependent modules will adjust accordingly.
Allow arguments to be used on the list of dependencies, this facilitates
searching for things like e.g. Boost, and there is now only need for one
list since REQUIRED can be one of the arguments.
Modules that starts with the prefix "Use" alters the build to enable
something by default, whereas modules that only provide functionality
is not common to start with that prefix.
Search for known headers and library files that indicates that DUNE is
available on the system, and setup compiler and linker variables.
Unfortunately, this module has hard-coded some knowledge of the
dependencies on other modules, and knowledge of which symbols that
should be defined. This information must be revised whenever a new
version of DUNE is released, because it is hard and error-prone to
infer this automatically.
As for the name of the modules, see the comment by mblatt at 2012-05-22
in the thread about CMake evaluation in the DUNE user forum:
<http://www.dune-project.org/flyspray/index.php?do=details&task_id=1000>
