Meaning of a Shakepeare verse?

Question:

Meaning of a Shakepeare verse?

Hi, I'm an Allistair Macclean fan, and the title of one of his books/movies (Where Eagles Dare) is taken from Shakespeare's "Richard III", specifically the lines,

I cannot tell: the world is grown so bad,
That wrens make prey where eagles dare not perch:
Since every Jack became a gentleman
There's many a gentle person made a Jack.

What is the exact meaning of this statement? And if anyone can point out some good websites where I can:
1) find Shakespeare's plays/sonnets in their entirety
2) get interpretations of language of his works (In high school we covered Macbeth, and the book we used had the interpretations of the words right along with the work itself, VERY useful)

THANKS!!!!!

Best Answer - Chosen by Asker: I think that maybe what Gloucester is saying here is that his world is topsy turvy and nothing is the way that it was; everything is upside down from point of view.

Here are some websites with all kinds of Shakespeare information:
http://shakespeare.mit.edu/
http://absoluteshakespeare.com
http://www.shakespeare-online.com/...