Fix .inf.java and .inf.mj tests

See merge request !11

Previously, there was a race condition between the RLIMIT_CPU timeout
(which resulted in a SIGKILL return code, meaning test failure) and the
subprocess.Popen.communicate timeout (which resulted in a
subprocess.TimeoutExpired exception that was converted to a SIGXCPU
return code, meaning test success). This meant that .inf.java and
.inf.mj tests would semi-consistently fail.

This fixes that issue by increasing the RLIMIT_CPU timeout to five
seconds longer than the subprocess.Popen.communicate timeout. I won't
pretend that this is anything but a quick dirty fix, but at least it
matches the style of the rest of mjtest.

Fix rlimits being set to floats (for Python 3.10)

Closes #11

See merge request !9

From what I can tell, rlimits must be integral values. In Python 3.10,
floats are not converted any more, instead a ValueError is thrown, which
breaks mjtest horribly.

Revert "Removed the compilation timeout"

See merge request !8

This reverts commit f290b58b.

Correct output alignment in result overview

See merge request !7

Respect "all_exec_tests" CLI flag

See merge request !6

This changes the output from
```
[SUCCESS] ast:AssignmentExpressionStatementAfterIf.valid.mjcorrect
[SUCCESS] ast:BlockStatement.mj                   correct
[SUCCESS] ast:Braces.valid.mj                     correct
[SUCCESS] ast:ComplexExpression.valid.mj          correct
[SUCCESS] ast:DeeplyNestedCalc.valid.mj           correct
[SUCCESS] ast:DerCompilerMain.valid.mj            correct
[SUCCESS] ast:Empty.valid.mj                      correct
[SUCCESS] ast:EmptyClassNamedStaticMethod.mj      correct
[SUCCESS] ast:EveryPossibleLanguageConstruct.valid.mjcorrect
```

to
```
[SUCCESS] semantic:FlushInStream.invalid.mj                          correct
[SUCCESS] semantic:InvalidAssignment3.invalid.mj                     correct
[SUCCESS] semantic:IntAssignmentInIf.invalid.mj                      correct
[SUCCESS] semantic:ExpressionStatementWithoutSideEffects.invalid.mj  correct
[SUCCESS] semantic:InvalidTypeOnAssignment.invalid.mj                correct
[SUCCESS] semantic:FibonacciViaLocalVars.valid.mj                    correct
[FAIL   ] semantic:LargeNegativeIntegerLiteral.invalid.mj            incorrect return code
```

Before this patch, this flag was always set to "True" when running
tests.

Multimodal test runs

See merge request !4

Fix #9

mandelbrot_mutable and index_overflow_test2 seem to run into this limit
and crash with "SIGSEGV: Resource temporarily unavailable".

Fix #6

fixup 558cba13: bump tests repo to published version

See merge request !3

558cba13 broke submodule update --init:

    git clone https://git.scc.kit.edu/IPDSnelting/mjtest.git && \
          cd mjtest && \
          git submodule update --init

    Cloning into 'mjtest'...
    remote: Enumerating objects: 788, done.
    remote: Counting objects: 100% (788/788), done.
    remote: Compressing objects: 100% (391/391), done.
    remote: Total 788 (delta 437), reused 725 (delta 392)
    Receiving objects: 100% (788/788), 162.16 KiB | 3.45 MiB/s, done.
    Resolving deltas: 100% (437/437), done.
    Submodule 'tests' (https://git.scc.kit.edu/IPDSnelting/mjtest-tests) registered for path 'tests'
    Cloning into '/tmp/mjtest/tests'...
    warning: redirecting to https://git.scc.kit.edu/IPDSnelting/mjtest-tests.git/
    warning: redirecting to https://git.scc.kit.edu/IPDSnelting/mjtest-tests.git/
    warning: redirecting to https://git.scc.kit.edu/IPDSnelting/mjtest-tests.git/
    error: Server does not allow request for unadvertised object 78b27a109cb1a1a6bc6d3a6e0f57b5018305530c
    Fetched in submodule path 'tests', but it did not contain 78b27a109cb1a1a6bc6d3a6e0f57b5018305530c. Direct fetching of that commit failed.

Fix #5

Fix #2 and #1