Update .gitignore

remove *.apk in .gitignore
fixed eclipse projects
Merge branch 'master' of github.com:secure-software-engineering/DroidBench into develop

Conflicts:
	.gitignore
	eclipse-project/AndroidSpecific_Library1/bin/androidspecific_library1.jar
	eclipse-project/GeneralJava_Obfuscation1/.settings/org.eclipse.jdt.core.prefs