Merge branch 'master' into issue549

Conflicts:
	res/menu/accounts_context.xml
	res/menu/accounts_option.xml
	res/values/strings.xml
	src/com/fsck/k9/Account.java
	src/com/fsck/k9/activity/Accounts.java
	src/com/fsck/k9/activity/AsyncUIProcessor.java
	src/com/fsck/k9/activity/FolderList.java
	src/com/fsck/k9/activity/ImportListener.java
	src/com/fsck/k9/activity/K9Activity.java
	src/com/fsck/k9/activity/K9ListActivity.java
	src/com/fsck/k9/activity/MessageView.java
	src/com/fsck/k9/mail/store/ImapStore.java
	src/com/fsck/k9/mail/store/Pop3Store.java
	src/com/fsck/k9/mail/store/WebDavStore.java
	src/com/fsck/k9/mail/transport/SmtpTransport.java