GENESIS 2.4 - Release Candidate (installfix)

This is the Release Candidate version of GENESIS 2.4 (rc2 with some bugfixes to the install process). It features a new autoconf-based build system (the legacy Makefiles were kept for backwards compatibility). The documentation is still in the process of being updated but will be part of the final 2.4 release. The full release is going to be through the official GENESIS website, handled by @dbeeman.