VS: Fix exclusion of projects from solution.

If a target wasn't build in some configurations _and_ didn't have these
configurations listed in "configurations" (directly or inherited; in any
case, quite understandable situation), then the exclusion would be
ignored and the generated .sln would keep the corresponding project
enabled.

Fixed to consider all configurations defined in the whole model.

src/bkl/plugins/vsbase.py

@@ -567,7 +567,7 @@ class AdditionalDepsFolder: pass
                         outf.write("\t\t{%s}.%s|%s.ActiveCfg = %s|%s\n" % (guid, cfg.name, plat, cfgp.name, platp))
                     else:
                         outf.write("\t\t{%s}.%s|%s.ActiveCfg = %s|%s\n" % (guid, cfg.name, plat, cfgp.name, platp))
-                        if cfgp not in prj.disabled_configurations:
+                        if cfg not in prj.disabled_configurations:
                             outf.write("\t\t{%s}.%s|%s.Build.0 = %s|%s\n" % (guid, cfg.name, plat, cfgp.name, platp))
         outf.write("\tEndGlobalSection\n")
         outf.write("\tGlobalSection(SolutionProperties) = preSolution\n")
@@ -750,7 +750,13 @@ def get_project_object(self, target):
                 warning("target type \"%s\" is not supported by the %s toolset, ignoring",
                         target.type.name, self.name)
                 return None
-        proj.disabled_configurations = [x.config for x in target.configurations
+
+        # See which configurations this target is explicitly disabled in.
+        # Notice that we must check _all_ configurations visible in the solution,
+        # not just the ones used by this target.
+        all_global_configs = (ConfigurationProxy(target, x)
+                              for x in target.project.configurations.itervalues())
+        proj.disabled_configurations = [x.config for x in all_global_configs
                                         if not x.should_build()]
         return proj