shells/ksh-devel: Update to latest github commit plus additional fixes

Main changes:

• Removal of obsolete comments and build system workarounds.
• Update build/test command invocations.
• Add -j${MAKE_JOBS_NUMBER} flag to enable parallel building (I added support for this last year).
• Ensure that ${SH} (/bin/sh) is used for shell actions while building.
• Install default shell functions in /usr/local/share/fun (for use with FPATH and the autoload command). Symlink /usr/local/share/examples/ksh* to that. (Of course you may decide to handle this differently, but it would be good if the canonical share/fun directory were available.)
• Install the version with dynamic (*.so*) libraries by default (the STATIC option can now be used to link those libraries statically). The version with the libraries is preferred because this enables access to all the libcmd built-ins (which are bound to /opt/ast/bin by default) and allows writing C programs that link against these libraries -- you can even embed the entire shell as a library. It would be good if this received wider testing.
• Install development headers and section 3 manual pages if the dynamic libraries are installed.

Submitted by: Martijn Dekker <martijn@inlv.org>

		ksh93 upstream