Make Evergreen link to the OpenSRF JavaScript files, rather than copy them.

Make Evergreen link to the OpenSRF JavaScript files, rather than copy them.

This means that if you upgrade OpenSRF, you will automatically get the
upgraded OpenSRF JavaScript in your Evergreen instance without having to
manually copy the files into the multiple places they live. Your Dojo
layer will still need to be recreated, however.

Also, use the autoconf AC_PROG_LN_S and AC_PROG_MKDIR_P macros to provide
better cross-platform support for these commands.

git-svn-id: svn://svn.open-ils.org/ILS/branches/rel_1_6@15445 dcc99617-32d9-48b4-a31d-7c20da2025e4