* backends: Add a Visual Studio 2013 backend
This is more-or-less a quick port from the VS2015 backend, except that
we update the Visual Studio version strings and toolset versions
accordingly. Also correct the generator string for Visual Studio 2015
in mesonbuild/cmake/common.py.
* backend: Add VS2012 backend
Similar to what we did for Visual Studio 2013, add a Visual Studio 2012
backend.
* vs2010backend.py: Implement `link_whole:` if needed
We actually need Visual Studio 2015 Update 2 to use `/WHOLEARCHIVE:`,
which is what we are currently using for `link_whole:` on Visual Studio.
For Visual Studio versions before that, we need to expand from the
static targets that were indicated by `link_whole:`, and any of the
sub-dependent targets that were pulled in via the dependent target's
`link_whole:`. This wil ensure `link_whole:` would actually work in
such cases.
* vs2010backend.py: Handle objects from generated sources
Unforunately, we can't use backends.determine_ext_objs() reliably, as
the Visual Studio backends handle this differently.
* vs2010backend.py: Fix generating VS2010 projects
Visual Studio 2010 (at least the Express Edition) does not set the envvar
%VisualStudioVersion% in its command prompt, so fix generating VS2010
projects by taking account into this, so that we can determine the location
of vcvarsall.bat correctly.
* whole archive test: Disable on vs2012/2013 backends too
The Visual Studio 2012/2013 IDE has problems handling the items that would be
generated from this test case, so skip this test when using
--backend=vs[2012|2013]. This test does work for the Ninja backend when
VS2012 or VS2013 is used, though.
Consolidate this error message with XCode along with the vs2010 backend.
* docs: Add the new vs2012 and vs2013 backends
Let people know that we have backends for vs2012 and 2013. Also let
people know that generating Visual Studio 2010 projects have been fixed
and the pre-vs2015 backends now handle the `link_whole:` project option.
This is done with the new cmake subprojects options object
that is similar to the already exisiting configuration data
object. It is consumed by the new `options` kwarg of the
cmake.subproject function.
Daniel Mensinger