upgrade to v3.6, upgrade android-maven-plugin, prepare for maven central, change packaging to aar
Merge branch 'master' of https://github.com/avianey/facebook-api-android-maven

Conflicts:
	facebook/pom.xml
	facebook/src/main/java/com/facebook/AppEventsLogger.java
	facebook/src/main/java/com/facebook/FacebookSdkVersion.java
	facebook/src/main/java/com/facebook/Request.java
Update pom to v3.6.0