Comminnted DB Support to exyus - almost fully baked!

[mca]

i've spent a good chunk of time beating on the XmlSqlResource class in
exyus this week. and i found a few glitches. along the way i've
revamped the support for handling exception rendering (now tied more
closely to the representation headers ((Accept/Content-Type) and i've
improved the details of POST-ing for update and delete (via a 'proxy
pattern' that i'll blog about soon). i also tweaked a few other things
in the engine this week. all good stuff.

however...

because of the time i spent updating *and* because of some personal
issues this week, i'm not ready to release a new runtime update
[sigh]. this next one will be a version bump (0.5 to 0.6) and i still
need to sort out some details. that means it will be three weeks (at
least) since the last runtime update - bad stuff.

hopefully, i can put together the details of the runtime during the
week and release soon.