mod_isapi: Simply backport the host of fixes for compilation on unix,

PR#'s 15993 29098 30022 16637 30033 28089
by pushing to trunk/ rev 416293 of modules/arch/win32/mod_isapi.[ch]
which compiles without changes.

+1 wrowe , fielding, jerenkrantz


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@463467 13f79535-47bb-0310-9956-ffa450edef68