Introduce `Library.uk`

This new file represents the first step towards proper versioning support of
external microlibrary in Unikraft.  The file itself acts as mechanism for
holding metadata-only values about the microlibrary.  This metadata is designed
to be compatible with GNU Make whilst simultaneously being human-readable and
readable by programs that are not GNU Make (e.g. tools such as KraftKit).

An important feature of this file is the inclusion of microlibrary versions.
In a later step, once relevant integrations have been made to Unikrat's core
build system and to relevant tools such as KraftKit, the user will be able to
see and select from different versions of the microlibrary.

In this initial commit, the relevant metadata is absorbed from both Makefile.uk,
Config.uk, but also includes new information such as SPDX License identifier.

Signed-off-by: Alexander Jung <alex@unikraft.io>
Approved-by: Razvan Deaconescu <razvand@unikraft.io>
Reviewed-by: Razvan Deaconescu <razvand@unikraft.io>
GitHub-Closes: #3

Update README & CONTRIBUTING

Reformat to Markdowm.
CONTRIBUTING: remove obsolete references, point users at unikraft website
README: clean up & simplify wording, point users at website

Signed-off-by: Andrei Tatar <andrei@unikraft.io>
Reviewed-by: Maria Sfiraiala <maria.sfiraiala@gmail.com>
Approved-by: Razvan Deaconescu <razvand@unikraft.io>
Tested-by: Unikraft CI <monkey@unikraft.io>
GitHub-Closes: #2

Update to upstream 1.13.0

Signed-off-by: Andrei Tatar <andrei@unikraft.io>
Reviewed-by: Maria Sfiraiala <maria.sfiraiala@gmail.com>
Approved-by: Razvan Deaconescu <razvand@unikraft.io>
Tested-by: Unikraft CI <monkey@unikraft.io>
GitHub-Closes: #2

Remove obsolete documentation files

Signed-off-by: Andrei Tatar <andrei@unikraft.io>
Reviewed-by: Maria Sfiraiala <maria.sfiraiala@gmail.com>
Approved-by: Razvan Deaconescu <razvand@unikraft.io>
Tested-by: Unikraft CI <monkey@unikraft.io>
GitHub-Closes: #2

Correct license headers introduced by University Politehnica of Bucharest

This commit removes the additional clause
"THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY"
from BSD license headers that got introduced by mistake
with the following commits:
 71df308 - Initial port of googletest to Unikraft (Vlad-Andrei BĂDOIU (78692))

On the one hand, this additional clause is redundant because
the BSD license already states that it must remain and the
copyright notice must be kept.
On the other hand, the clause freezes the file header
and prohibits future contributors from extending the
copyright notice for their contributions. This additional
clause is not part of the official BSD 3-clause.

The original author(s) or an authorized representative from
the author's affiliation consents to the change with a
`Reviewed-by` tag to this commit.

Signed-off-by: Simon Kuenzer <simon.kuenzer@neclab.eu>
Reviewed-by: Razvan Deaconescu <razvan.deaconescu@cs.pub.ro>

Initial port of googletest to Unikraft

This is our initial port of googletest to Unikraft as an external
library. libcxx is required. This library should be added last to the
dependency list, e.g.,:

    ...:$(UK_LIBS)/libunwind:$(UK_LIBS)/compiler-rt:$(UK_LIBS)/libcxxabi:
        $(UK_LIBS)/libcxx:$(UK_LIBS)/newlib:$(UK_LIBS)/googletest:...

This library has a config option called LIBGOOGLETEST_BUILD_MAIN that builds the
gtest_main.cc file; this is because some libraries do not have any main function
in their unit tests and expect googletest to provide it.

Signed-off-by: Vlad-Andrei Badoiu <vlad_andrei.badoiu@stud.acs.upb.ro>
Reviewed-by: Felipe Huici <felipe.huici@neclab.eu>

Add documentation

Signed-off-by: Vlad-Andrei Badoiu <vlad_andrei.badoiu@stud.acs.upb.ro>
Reviewed-by: Felipe Huici <felipe.huici@neclab.eu>

Add .gitignore

Signed-off-by: Vlad-Andrei Badoiu <vlad_andrei.badoiu@stud.acs.upb.ro>
Reviewed-by: Felipe Huici <felipe.huici@neclab.eu>

Initial commit (empty)