README

This is a multi-step process to build GnuR in such a way that FASTR can use some of the libraries.
After building GnuR we extract configuration information for use in building packages in the FastR environment.
This goes into the file platform.mk, which is included in the Makefile's for the standard packages built for FastR.
The main change is to define the symbol FASTR to ensure that some important modifications to Rinternals.h are made
(e.g. changing an SEXP to a JNI jobject).