Merge branch 'linked-identities' (and fix OperationHelper ids)

Merge Linked Identities.

Also includes an important fix for OperationHelper ids, which had an
error in the bit mask logic.

Conflicts:
	Graphics/update-drawables.sh
	OpenKeychain/build.gradle
	OpenKeychain/src/main/java/org/sufficientlysecure/keychain/operations/results/OperationResult.java
	OpenKeychain/src/main/java/org/sufficientlysecure/keychain/provider/KeychainProvider.java
	OpenKeychain/src/main/java/org/sufficientlysecure/keychain/provider/ProviderHelper.java
	OpenKeychain/src/main/java/org/sufficientlysecure/keychain/service/CertifyActionsParcel.java
	OpenKeychain/src/main/java/org/sufficientlysecure/keychain/service/KeychainIntentService.java
	OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/CreateYubiKeyImportFragment.java
	OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/KeyListFragment.java
	OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ViewKeyActivity.java
	OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/adapter/KeyAdapter.java
	OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/widget/CertifyKeySpinner.java
	OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/widget/KeySpinner.java
	OpenKeychain/src/main/res/anim/fade_in.xml
	OpenKeychain/src/main/res/anim/fade_out.xml
	OpenKeychain/src/main/res/layout/decrypt_text_fragment.xml
	OpenKeychain/src/main/res/layout/encrypt_decrypt_overview_fragment.xml
	OpenKeychain/src/main/res/layout/view_key_fragment.xml
	OpenKeychain/src/main/res/menu/key_view.xml
	OpenKeychain/src/main/res/values/strings.xml
	OpenKeychain/src/test/java/org/sufficientlysecure/keychain/operations/CertifyOperationTest.java
	README.md

OpenKeychain/src/main/res/values/attr.xml

@@ -33,4 +33,8 @@
         <attr name="color_strong" format="color" />
     </declare-styleable>
 
+    <declare-styleable name="PrefixedEditText">
+        <attr name="prefix" format="string" />
+    </declare-styleable>
+
 </resources>