checked in minor changes to exyus

[mca]

i checked in two minor changes to the exyus code tree this evening.

the first is a spelling change for an internal argument for one of the
constructors of the HTTPClient class. the second change is the
addition of "public bool NoCache" property to the CollectionRequestor
class in the same code file. this does not change the default behavior
(defaults to true) but offers the option of turning off the "no-cache"
behavior of the <code>CollectionRequestor</code> class.

these are minor, i know. i've been swamped with other things over the
last two weeks. i hope to dive back into coding this coming weekend. i
have some tutorial articles to finish up as well. maybe i can post one
of those before the weekend arrives.