"Requirements and compilation instructions" are outdated

The "Requirements and compilation instructions" (link from the GeoAPI home page) are now outdated. We need to update it with a better explanation of the build process. This build process would be simplier if the CVS contains the code in its J2SE 1.5 form (reminder: the build process generate the javadoc from this J2SE 1.5 form, and then remove the 1.5 specific features in order to get a J2SE 1.3 compilable code).