Log Message:
We allow several JDKs/JREs to coexist, installing them in separate
subdirectories under ${PREFIX}/java/ -- Change I of many.

Thus, for consistency, also install kaffe into ${PREFIX}/java/kaffe
rather than ${PREFIX}/java

While we're at it, update kaffe to version 1.0.7.
Changes since 1.0.6:
- New version of KJC
- New encoding converters based on iconv().
- Lots of bug fixes

Furthermore, the website says that 1.0.7 has added support for
Darwin, ia64 GNU/Linux, s390 GNU/Linux, PA-RISC GNU/Linux, Alpha for
Compaq Tru64 GNU/Linux and support of PowerPC without libffi.
People with access to any of these platforms are encouraged to test
this version, so we can possibly adjust ONLY_FOR_PLATFORMS etc.