Made major changes to only depend on fields, split long strings to multi-attributes, added OFFSET keyword support, and serialize objects to Base64.

WARNING: Had to comment out foreign key and lobkey support due to its dependencies on beans and enhancers. Will re-add them when I have time to do it without beans and enhancers.
WARNING: core/tests will have some commented/removed code, will add proper tests concerning the major changes.

Removed most dependencies on get/set methods, beans, and enhancers.
(There are still some enhancers and beans somewhere, but most of them shouldn't be used)
Long strings get split to multiple attribute/value pairs (most code from https://github.com/appoxy/simplejpa/pull/5 , adapted for more recent changes in SimpleJPA)
Any serializable objects in members will be serialized into Base64 string (uses long strings split change).
Added OFFSET keyword support, which does a count query and uses the next token to get wanted items (as suggested by AWS people).
Added utility constructor in EntityManagerFactoryImp.
SimpleJPA should ignore static fields now.

Updated README.markdown (and fixed some stuff so it's actually readable).

Signed-off-by: jayther <jayther@gmail.com>