Revert "make partial_build work in separate builddir"
Revert "make partial_build work in separate builddir"

This reverts commit 207e370a167b7856346c1bff0c735cd2688e2e6e.

This breaks the module build i.e. cd <module> && make.

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core