Allow user to explicitly determine whether or not BSD syntax

makefiles should be created... The default is NO unless we
are on a *BSD* system, in which case we actually see if
'make' is gmake or not.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1553134 13f79535-47bb-0310-9956-ffa450edef68