Added test for basic wasm contract loading/unloading.  Fixed bugs in the intrinsic code and made it impossible to complile with the same class of bugs in the future.  Did some basic style/renaming in the contracts directory and in the enclosed tutorial/doxygen files

Changed to only compile a wasm target cpp file and require multiple cpp files for a target be included in the target cpp file.

* Copy .abi files to build folder for smart contracts
* Update README.md to reflect the change