Rename raii to scope_guard, re-implement as a template,
instead of using std::function.
Use to avoid some boilerplate in tpanelparentwin_nt_impl::PushTweet.
Fix race condition when a new tweet arrived during a jump to tweet in
which all currently displayed tweets in the panel were removed, before
the first new tweet became ready for display.
Fix parsing of 'favorited' perspectival tweet property.
Fix tweet favorited/retweeted perspectival properties being reset to
false if not present when being parsed.
Replace more DB boilerplate with calls to utility functions.
Refactor DBInitialiseSql to return a wrapper with unique_ptr semantics,
where the returned statement should be freed.
Remove DBUnInitialiseSql.