Local runner - round 3

[kaste]

This PR has three parts.

• First three commits tell docker/rsync to not sync gitignored files.
  That is really a speed-up if you have temp files or a .venv directory
  in the package dir.

• Then there are a couple of simple maintenance commits.

• Then, the bigger feature, I teach the runner to run syntax tests.
  E.g. ut-run-tests . will now run unit tests, syntax tests, and syntax
  compatibility tests in one go, (--no-unit-tests --no-syntax-tests --no-syntax-compatibility-checks to tweak the default.) and the --file
  will work by our naming conventions

  ut-run-tests . --file tests/test_example.py
  ut-run-tests . --file syntax_test_example
  ut-run-tests . --file Example.sublime-syntax
  

In general, only docker/ and sbin/ files have been touched, but the syntax tests
need a small extension to unittesting/syntax.py:

• By default, these commands failed loud ("red") if invoked and no tests could
  be found. (Unlike UnitTesting, which just says "0 tests run. OK.")
  This behavior can now be flipped by using the option fail_if_no_resources.

  Without that change we would need to duplicate the find_resources logic in
  the runner, so that it only invokes the actual tests if such resources can be
  found. That seemed like needless duplication.

• We allow pattern and tests_dir for these commands now as well. This is
  to support file selection (--file).

Example

$ time ut-run-tests . --file syntax/test/syntax_test_blame.txt
Package root: C:\Users\kaste\AppData\Roaming\Sublime Text\Packages\GitSavvy
Package name: GitSavvy
Docker image: unittesting-local
Scheduler delay: 0ms
Cache volume: unittesting-home
Cache lock: enabled
Test categories: syntax-tests
Test target: syntax/test/syntax_test_blame.txt
Package sync: Git-ignored files excluded
PACKAGE = GitSavvy
Starting virtual X frame buffer: Xvfb.
Running command: copy_tested_package overwrite
sync package into sublime package directory
Running command: copy_tested_package overwrite
sync package into sublime package directory
Running command: run_test_categories --syntax-tests -- --color auto --tests-dir syntax/test --pattern syntax_test_blame.txt
Runtime:
  Sublime Text: Sublime Text Build 4200
  Package Control: 4.2.7
Schedule:
  package: GitSavvy
  coverage: None
  reload_package_on_testing: False
  pattern: syntax_test_blame.txt
  tests_dir: syntax/test
  fail_if_no_resources: False
  syntax_test: True
  output: /root/.config/sublime-text/Packages/User/UnitTesting/GitSavvy/result
Wait for syntax tests output....
=== SYNTAX TESTS OUTPUT ===
Success: 22 assertions in 1 file passed
OK

UnitTesting: Done.

real    0m3,618s
user    0m0,060s
sys     0m0,016s