Long click on repo opens dialog

1) Navigate to repo owner's page
2) Remove repository from Recently Viewed

Also now refreshes repositories list when you return from
viewing a repo if the repo was added to the Recently Viewed list.
Previously, you had to manually refresh for the change to be seen.

Closes #348
Revert AvatarLoader whitespace changes
correct content description for avatar image
remove useless layout
imports optimize
extract string to resources