Version 0.3.18

Added selective quoting for Android 3.0 and up - long press on text in a
post to select it, use the tabs on the end of the selection to modify
what text is selected, then click the post header and click quote to
just quote the selected text (this feature is restricted to 3.0 and up
because selecting text in a TextView is unsupported at an OS level on
lower versions)
Added highlighted users to backup + restore system
Added handling of empty responses from the server (treated as a timeout
- this is something I can't reliably test, and seems to be an
intermittent issue with only some users)
Fixed display of polls that have been voted in