When install_dir was set for a shared_library, the import library
would not be installed at all, which is unintended.
Instead, install it into the custom directory if it is set, otherwise
install it in the default import library installation directory.
Includes a test for this.
In this test, we try to manually link against the generated library to
create an executable and then run it to verify that it works.
Also test for all possible library versioning in the versioning tests on
Windows. Even though they yield the same dll naming, we should still
test it.
Also add new tests for the platform-specific and compiler-specific
versioning scheme.
A rough summary is:
1. A bug in how run_tests.py:validate_install checked for files has been
fixed. Earlier it wasn't checking the install directory properly.
2. Shared libraries are no longer installed in common tests, and the
library name/path testing is now done in platform-specific tests.
3. Executables are now always called something?exe in the
installed_files.txt file, and the suffix automatically corrected
depending on the platform.
4. If a test installs a file called 'no-installed-files', the installed
files for that test are not validated. This is required to implement
compiler-specific tests for library names/paths such as MSVC vs MinGW
5. The platform-specific file renaming in run_tests.py has been mostly
removed since it is broken for shared libraries and isn't needed for
static libraries.
6. run_tests.py now reports all missing and extra files. The logic for
finding these has been reworked.