- Added package doc for crypto and net.i2p

- Got rid of some susimail javadoc warnings

core/java/src/net/i2p/crypto/package.html

@@ -0,0 +1,11 @@
+<html>
+    <body>
+        <p>
+            These classes provide a number of low-level cryptographic routines.
+        </p>
+
+        <p>
+            These cryptographic routines include symmetric and asymmetric encryption and decryption, hashing, secure random number generation...
+        </p>
+    </body>
+</html>

core/java/src/net/i2p/package.html

@@ -0,0 +1,7 @@
+<html>
+    <body>
+        <p>
+            Core I2P package, contains information about the I2P version and an entry point to access important elements.
+        </p>
+    </body>
+</html>