Improve it by the following:
1) Also check xxd source
2) Test_source_files():
don't stop on the first error found, continue until the
end of the file and report all found errors like this:
Signed-off-by: Christian Brabandt <cb@256bit.org>
Problem: Errors from the codestyle test are a bit confusing.
Solution: Use assert_report() with a clearer message. Avoid a warning for
an existing swap file.
Problem: No test for bad use of spaces in help files.
Solution: Add checks for use of spaces in help files. Ignore intentional
spaces. (Hirohito Higashi, closes#11952)
