add '--date' to opts_query_modifiers
add '--devel' to sync option

"--devel" exists in query, but "yaourt -Syu --dev<tab><tab>" issn't autocompleting "--devel" (not sure it should based on it being in the query call, just wanted to mention it).
Merge pull request #154 from panth0r/master

Add --date option for "yaourt -Q"