Better error handling

OpenPGP-Keychain/src/org/sufficientlysecure/keychain/service/exception/NoUserIdsException.java

@@ -0,0 +1,10 @@
+package org.sufficientlysecure.keychain.service.exception;
+
+public class NoUserIdsException extends Exception {
+
+    private static final long serialVersionUID = 7009311527126696207L;
+
+    public NoUserIdsException(String message) {
+        super(message);
+    }
+}

OpenPGP-Keychain/src/org/sufficientlysecure/keychain/service/exception/UserInteractionRequiredException.java

@@ -0,0 +1,10 @@
+package org.sufficientlysecure.keychain.service.exception;
+
+public class UserInteractionRequiredException extends Exception {
+
+    private static final long serialVersionUID = -60128148603511936L;
+
+    public UserInteractionRequiredException(String message) {
+        super(message);
+    }
+}

OpenPGP-Keychain/src/org/sufficientlysecure/keychain/service/exception/WrongPassphraseException.java

@@ -0,0 +1,10 @@
+package org.sufficientlysecure.keychain.service.exception;
+
+public class WrongPassphraseException extends Exception {
+
+    private static final long serialVersionUID = -5309689232853485740L;
+
+    public WrongPassphraseException(String message) {
+        super(message);
+    }
+}