* Fix error message
* Improve comments
* Improve target names
* Fix working directory for check target
* Add info that calling enable_testing() on root
level is required for check target to work
* Create workingdir for tests under binary dir to
prevent polluting source dir
When LINK_TESTS_AGAINST_APP_TARGET set, create a
library in addition to the application so tests can
link against it to check particular functions. This
replaces the current approach of linking against the
application directly which lead to linker errors.
- Ensure static versions of 3rd party libs are
found correctly
- Link tests against statically if only static
libraries have been built
- Ensure standard lib is linked statically when
static linkage is enabled