Implemented Android Smart Card Emulator

Includes jCardSim to emulate the following Java Card Applets in
Android's host card emulation:

- jCardSim Team's Hello World Applet
- Philip Wendland's ISO Applet
- Yubico's OpenPGP Applet
- Yubico's OATH Applet

ACardEmulator/.gitignore

@@ -0,0 +1,6 @@
+.gradle
+/local.properties
+/.idea/workspace.xml
+/.idea/libraries
+.DS_Store
+/build