i2p project overview doc for the SDK

here's a draft of the doc referred to in the readme i posted the other
day.  it may or may not be more controversial than usual, since it has
some philosophy that not everyone on the team may fully agree with (what,
 you mean you aren't all militant anarchists too?).  

so, from what I can see, we're definitely going to have the I2P SDK ready
for 0.1 release next week [since, well, technically, we have it all now
and all thats left is wrapping 'er up]

So, please, read this and the readme over asap and get your comments
and ideas in so the docs can be adjusted.

-jrandom