Use the javascript library select2 to autocomplete descriptions and
account names when adding a transaction. The autocomplete searches by
substring, prefix and infix. New values will also be accepted.
This replaces dhtmlxcombo library so it is removed. Also updated jquery
to the latest 1.10.1.
The web app's journal state is now kept in the yesod App as an IORef,
instead of using io-storage.
yesod devel now works; it uses the journal file specified by
$LEDGER_FILE, or ~/.hledger.journal.
web: update journal state handling, fix yesod devel - WIP