feat(xslt): coverage reporter for SonarQube

[VTristan]

Proposal for issue #877
I propose to answer this issue by adding a new stylesheet coverage-sonar-report.xsl and by factoring coverage-report.xsl.

The new report generated, corresponds to the generic format of SonarQube.

Just change the environment variables.
e.g on windows:
set "COVERAGE_REPORTER_XSL=%XSPEC_HOME%\src\reporter\coverage-sonar-report.xsl"
set "COVERAGE_HTML=%TEST_DIR%\%TARGET_FILE_NAME%-sonar-coverage.xml"

(I did a second fork, to offer a cleaner and more up-to-date PR).

[AirQuick]

Thanks for restarting the pr, @VTristan
Unfortunately some problems still persist:

• Every line in coverage-report.xsl is considered modified, due to line ending characters. See the diff.

• If you run bin\xspec.bat -c tutorial\coverage\demo.xspec (without setting COVERAGE_REPORTER_XSL and COVERAGE_HTML), the imported module name in demo-coverage.html is wrong:

  module: .../tutorial/coverage/demo.xsl; 25 lines

  It should be

  module: .../tutorial/coverage/demo-imported.xsl; 25 lines

[AirQuick]

Now that #1014 is merged into the master, I think you can remove the predicate.

Suggested change

	<xsl:for-each select="$context[not(contains(@u,'xspec-utils.xsl'))]">
	<xsl:for-each select="$context">

[AirQuick]

If you merge the latest master into this branch and run

set COVERAGE_REPORTER_XSL=
set COVERAGE_HTML=
bin\xspec.bat -c test\end-to-end\cases\coverage-no-hit.xspec

then the generated coverage-no-hit-coverage.html looks like this. From there, you can understand that two stylesheets (coverage-no-hit.xsl and coverage-no-hit_included.xsl) are involved but not tested.

On the other hand, if you run

set COVERAGE_REPORTER_XSL=src\reporter\coverage-sonar-report.xsl
set COVERAGE_HTML=coverage-sonarqube.xml
bin\xspec.bat -c test\end-to-end\cases\coverage-no-hit.xspec

then the generated coverage-sonarqube.xml is

<coverage version="1"></coverage>

where you can't identify the two involved-but-untested stylesheets. Is that fine?