Merge branch 'sso'

# Conflicts:
#	.gitignore
#	README.md
#	build.gradle
#	gradle/wrapper/gradle-wrapper.jar
#	gradle/wrapper/gradle-wrapper.properties
#	src/main/java/de/luhmer/owncloud/accountimporter/helper/AccountImporter.java
#	src/main/res/values/strings.xml