add MobileIdentity as separate class, add test

Use fixed applet-project.mk to put Mobile Identity implementations in a
separate class MobileIdentity.java.

That allows trivially testing the MobileIdentity implementation outside of an
actual SIM card environment: add a 'test' target to the Makefile and a
Test.java class that runs some tests.
diff --git a/sim-applet/Makefile b/sim-applet/Makefile
index 0300b4e..740ffd8 100644
--- a/sim-applet/Makefile
+++ b/sim-applet/Makefile
@@ -6,7 +6,8 @@
 PACKAGE_NAME    = org.osmocom.IMSIPseudo
 PACKAGE_VERSION = 1.0
 
-SOURCES = src/org/osmocom/IMSIPseudo/IMSIPseudo.java
+SOURCES = src/org/osmocom/IMSIPseudo/MobileIdentity.java src/org/osmocom/IMSIPseudo/IMSIPseudo.java
+
 CAP_FILE = build/javacard/org/osmocom/IMSIPseudo/javacard/IMSIPseudo.cap
 
 include ./applet-project.mk
@@ -37,3 +38,10 @@
 		--kid "$$KID1"
 
 delete: remove
+
+.PHONY: test
+test:
+	mkdir -p ./test/classes
+	javac -target 1.1 -source 1.3 -classpath test/classes -g -d ./test/classes src/org/osmocom/IMSIPseudo/MobileIdentity.java
+	javac -target 1.1 -source 1.3 -classpath test/classes -g -d ./test/classes src/org/osmocom/IMSIPseudo/Test.java
+	java -classpath test/classes org.osmocom.IMSIPseudo.Test