Cleanup the `install' stuff:

INSTALL_SCRIPT for DSOs was confusing. Use an own define for this.
And be consistent: Don't display INSTALL_PROGRAM but do INSTALL_SCRIPT.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@82097 13f79535-47bb-0310-9956-ffa450edef68