split out reusable IOCipher util methods into a standalone Util class
update VirtualFileSystemTest to use mount() with key to enable encryption
Revert "Integrate IOCipherThreadTest submitted by Aaron Huttner"

This reverts commit 34c85f151beccd39bea9af9b4b85f304d7c7b2cc.

Since this is an Android app, remove it so this project remains only JUnit
tests. Then the ThreadTest can be refactored into a JUnit test to include.

Conflicts:

	.gitignore
	AndroidManifest.xml
	project.properties
	res/layout/main.xml
	src/info/guardianproject/iocipher/tests/ThreadTest.java
clarify debug messages related to deleting and creating the database file