Merge branch '41-alias-frontend-base' into 'master'

.../org/briarproject/bramble/api/contact/ContactManager.java

...ava/org/briarproject/bramble/api/identity/AuthorInfo.java

.../org/briarproject/bramble/contact/ContactManagerImpl.java

.../briarproject/bramble/contact/ContactManagerImplTest.java

...g/briarproject/briar/android/blog/BlogPostViewHolder.java

...project/briar/android/contact/BaseContactListAdapter.java

...rproject/briar/android/contact/ContactItemViewHolder.java

...iarproject/briar/android/contact/ConversationVisitor.java

...iar/android/introduction/IntroductionMessageFragment.java

.../privategroup/conversation/JoinMessageItemViewHolder.java

...id/privategroup/invitation/GroupInvitationViewHolder.java

...iarproject/briar/android/privategroup/list/GroupItem.java

...ar/android/privategroup/list/GroupListControllerImpl.java

...ject/briar/android/privategroup/list/GroupViewHolder.java

...ar/android/privategroup/memberlist/MemberListAdapter.java

...android/privategroup/memberlist/MemberListItemHolder.java

...roid/privategroup/reveal/RevealableContactViewHolder.java

...ct/briar/android/sharing/SharingInvitationViewHolder.java

...ject/briar/android/threaded/BaseThreadItemViewHolder.java

...a/org/briarproject/briar/android/threaded/ThreadItem.java