Removing deprecated classes & deprecation policy

[Jaroslav Tulach]

Hi.
The version truffle-0.9 has been tagged in our repository, so it is time to 
start working on next iteration. The first thing I decided to do is to get rid 
of @Deprecated elements in the API: http://lafo.ssw.uni-linz.ac.at/hg/truffle/rev/414e82b9fc35

I would never do it, if the API was released in a stable form, but as we are 
still in development mode, I think such cleanup is OK. To give such removals 
some structure, I defined deprecation policy to set mutual expectations up. 
See bottom of
http://lafo.ssw.uni-linz.ac.at/javadoc/truffle/latest/overview-summary.html

I hope such deprecate/remove iterations will work for you, early adopters! If 
not, please speak up. Thanks.
-jt