Log Message:
Improve handling of "ZSH_STATIC" again:
1.) Only create a dynamically linked "zsh" binary if \ 
"MKDYNAMICROOT"
    is defined and set to "yes". This way people who still use statically
    linked binaries on their root filesystem will get a static binary.
2.) Link the "zsh" binary so that it use "/libexec/ld.elf_so" and
    shared libraries from "/lib". It now works without the "/usr"
    filesystem being mounted.