This teaches ctest_coverage() to remove any existing CoverageLog-*.xml
when it creates new coverage results. Otherwise the next ctest_submit()
may submit old coverage log files which unnecessarily.
This teaches CTest to process coverage information only for object files
in targets containing labels of interest. This change also improves
loading of global coverage information by globbing only in each target
support directory instead of the entire build tree.
This generalizes the previous CMakeFiles/LabelFiles.txt created at the
top of the build tree to a CMakeFiles/TargetDirectories.txt file. It
lists the target support directories for all targets in the project.
Labels can still be loaded by looking for Labels.txt files in each
target directory.
This teaches CTest to include source file labels in coverage dashboard
submissions. The labels for each source are the union of the LABELS
property from the source file and all the targets in which it is built.
Brad King
Bill Hoffman
Andy Cedilnik
Ken Martin