android: Add android build on travis-ci

This adds a android-apk-build which runs on travis-ci. This is using a
quite ugly trick, building in a docker container, basically just to get
a newer cmake. The cmake in trusty is way to old to work with android
builds.

A good side-effect is that this is a complete copy-paste for anyone who
would like to build android-binaries them self on Linux. All the
uglyness is hidden away in a docker container.

Signed-off-by: Anton Lundin <glance@acc.umu.se>

scripts/android/after_success.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+if [ ! -z $TRAVIS_BRANCH ] && [ "$TRAVIS_BRANCH" != "master" ] ; then
+	export UPLOADTOOL_SUFFIX=$TRAVIS_BRANCH
+fi
+
+echo "Submitting the folloing apk for continuous build release:"
+ls -lh $TRAVIS_BUILD_DIR/apk/*.apk
+
+# get and run the upload script
+wget -c https://github.com/probonopd/uploadtool/raw/master/upload.sh
+bash ./upload.sh $TRAVIS_BUILD_DIR/apk/*.apk

scripts/android/before_install.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+
+# Travis only pulls shallow repos. But that messes with git describe.
+# Sorry Travis, fetching the whole thing and the tags as well...
+git fetch --unshallow
+git pull --tags
+git describe
+
+# Ugly, but keeps it running during the build
+docker run -v $PWD:/workspace/subsurface --name=builder -w /workspace -d ubuntu /bin/sleep 60m
+docker exec -t builder apt-get update
+# subsurface android build dependencies
+docker exec -t builder apt-get install -y git cmake autoconf libtool-bin openjdk-8-jdk-headless ant wget unzip python bzip2 pkg-config
+# Qt installer dependencies
+docker exec -t builder apt-get install -y libx11-xcb1 libgl1-mesa-glx libglib2.0-0
+# Inject cached 3pp's (if none exists in 3pp dir, we inject zero ones, and all is downloaded in the container)
+# TODO: caching
+#docker cp 3pp builder:/workspace
+docker exec -t builder mkdir -p /workspace/3pp

scripts/android/travisbuild.sh

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+#!/bin/bash
+
+docker exec -t builder subsurface/packaging/android/android-build-wrapper.sh
+
+# Extract the built apk from the builder container
+docker cp builder:/workspace/subsurface-mobile-build-arm/build/outputs/apk/ .
+
+# TODO: Caching
+# Yank Qt, android-sdk, android-ndk and other 3pp source tar balls out from the container and cache them.
+#docker exec builder mkdir -p 3pp
+#docker exec builder sh -c 'mv Qt android-sdk-linux android-ndk-* *.tar.gz *.tar.bz2 3pp/'
+#docker cp builder:/workspace/3pp .