Add gradle library support
Update gradle for example sub-project
Service mode: allow multiple notifications (#18)
Cert dialog: replace MD5 with SHA-256
Refactor keystore writing into own method
New API methods to iterate over and delete stored certificates (fix #16)
MTM example: add certificate 'management' dialog
MTM example: bump target to KitKat; remove import
Added README with updated content from wiki
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/de/duenndns/ssl/MemorizingTrustManager.java
Update MTM Gradle setup to latest Android Plugin version