libc-test repo

[Szabolcs Nagy <nsz@port70.net>]

after trying various buildsystem things i decided to put
the new libc test system on top of my old libc-test repo
(in the end there aren't many new features in it)

http://nsz.repo.hu/git/?p=libc-test

i need to fix a few things in math and fiddle with the
build flags a bit but it should be usable
(other missing things: wrapper to run the tests with timeout
and report the exit status, 'make run' to rerun the dynamically
linked executables without building anything, build into
different directories with different build settings)

i added a top level copyright notice and authors file
most of the test should not be copyrightable but what do i know

i added the tests by kirill (tw1gz) after some cleanup
so the code has consistent style for now (there are no strict
style rules as the test cases are pretty much independent)

i ran the tests with 'CC=musl-gcc make' and 'CC=gcc make'
(the invalid errors will be eventually fixed)

see the readme for further details

(as discussed some libc tests will need special environment,
that is not yet in scope (containers, uml and seccomp came up
as solutions so far), libc source code inspection is not yet
in scope either but gcov/lcov coverage report would be nice
to set up)