Travis: add Windows build in a container

I expect this to become the default way to test Windows builds and
create installers on Travis. The idea is that instead of downloading the
pre-built MXE binaries we might as well use a container that has all
this installed and can be used locally to test if things fail on Travis;
which will allow us to have the exact same environment for testing
locally as runs on Travis.

At this point the container used is way too big - more effort needs to
be spent on shrinking it.

Right now this only deals with Subsurface and not with smtk2ssrf.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

scripts/windows-container/after_success.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+if [ ! -z $TRAVIS_BRANCH ] && [ "$TRAVIS_BRANCH" != "master" ] ; then
+	export UPLOADTOOL_SUFFIX=$TRAVIS_BRANCH
+fi
+
+cd ${TRAVIS_BUILD_DIR}/../win32/subsurface
+
+echo "Submitting the following Windows files for continuous build release:"
+find . -name subsurface\*.exe*
+
+# set up the release message to use
+source ${TRAVIS_BUILD_DIR}/scripts/release-message.sh
+
+# for debugging, let's look around a bit
+ls -la
+
+# the win32 dir is owned by root, as is all its content (because that's
+# the user inside the docker container, I guess. So let's create upload.sh
+# in the TRAVIS_BUILD_DIR
+cd ${TRAVIS_BUILD_DIR}
+
+# get and run the upload script
+wget -c https://raw.githubusercontent.com/dirkhh/uploadtool/master/upload.sh
+bash ./upload.sh ${TRAVIS_BUILD_DIR}/../win32/subsurface/subsurface*.exe*
+
+
+# upload smtk2ssrf
+#cd ${TRAVIS_BUILD_DIR}/../win32/smtk-import
+#bash ../subsurface/upload.sh smtk2ssrf*.exe*