Temporary workaround for issue #158 -- compile with _PORTABLE_VERSION defined and it will change the default for fs_homepath back to JKA's standard.
Revert "Temporary workaround for issue #158 -- compile with _PORTABLE_VERSION defined and it will change the default for fs_homepath back to JKA's standard."

This reverts commit fc6569207cc43ef850e9ca61da9385d0cd5fe6b4.
Correct workaround for issue #158 to allow custom portable versions.
Will need to implement it in cmake at a later time when an official portable build happens.