This patch makes style checks and warning as error switches controllable
with a scenario variable: ADL_BUILD_CHECKS (disabled by default).
With this we can enforce style checks on all contributions by enabling
ADL_BUILD_CHECKS in testsuite runs and CI builds.
On the other hand the checks are disabled by default which means it is
easier and more friendly to play with the library and the examples.
Part of #271
in a package called File_IO. This hides some of the complexity of
dealing with access to handle and answers some of the questions
discussed in the issue #68.
The package also provides the mounting interface, taken from
Filesystem.VFS.
This build dependency won't work anymore with the next GNAT release as
runtimes will now require being installed into the compiler.
This commit also now generates automatically the board projects, to ease
the addition of new boards and runtimes, as well as taking into account
modifications refactoring of the library.
