Build script for Debian

Add a script which builds the project on Debian
and produces an apk. This makes creating test builds
a little easier

tools/debian_build.sh

@@ -0,0 +1,51 @@
+#!/bin/bash
+
+# This script is intended to be used on Debian systems for building
+# the project. It has been tested with Debian 8
+
+USERNAME=$USER
+SIGNING_NAME='k-9'
+
+cd ..
+
+PROJECT_HOME=$(pwd)
+
+sudo apt-get install build-essential default-jdk android-tools-adb \
+     lib32stdc++6 lib32z1 lib32z1-dev gradle
+
+if [ ! -d ~/Android ]; then
+    echo -n 'Download android studio from http://developer.android.com/sdk/'
+    echo -n 'index.html and extract it to the the home folder, install, open'
+    echo -n 'the Sdk Manager and install Android 17 and Sdk tools for 19.1, '
+    echo 'then press any key...'
+    read -n 1 -s
+    cd ~/Android/Sdk/tools
+    echo ''
+    echo ''
+    echo -n 'You need to have pretty much everything installed. '
+    echo 'It will take some time.'
+    ./android sdk
+    cd $PROJECT_HOME
+fi
+
+echo "sdk.dir=/home/$USERNAME/Android/Sdk" > local.properties
+
+# install Gradle (if is not installed yet) and then execute Gradle
+./gradlew build
+
+#cd ~/develop/$PROJECT_NAME/build/outputs/apk
+#keytool -genkey -v -keystore example.keystore -alias \
+#    "$SIGNING_NAME" -keyalg RSA -keysize 4096
+#jarsigner -verbose -keystore example.keystore \
+#    k9mail-release-unsigned.apk "$SIGNING_NAME"
+
+# cleaning up
+cd $PROJECT_HOME/k9mail/build/outputs/apk
+if [ ! -f k9mail-release-unsigned.apk ]; then
+    echo 'k9mail-release-unsigned.apk was not found'
+    exit 648
+fi
+echo 'Build script ended successfully'
+echo -n 'apk is available at: '
+echo "$PROJECT_HOME/k9mail/build/outputs/apk/k9mail-release-unsigned.apk"
+exit 0