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

and resolve PR#'s 15993 29098 30022 16637 30033 28089
by pushing to trunk/ rev 416293 of modules/arch/win32/mod_isapi.[ch]
which compiles with the addition of [apr_]brigade_insert_file() as
cribbed from apr-util 1.x trunk.  delta previously posted at
  http://people.apache.org/~wrowe/mod_isapi-416293-to-httpd-2.0.patch
and broadly tested with positive results, with the exception of one
more patch incoming to handle ate == left edge case.

Previously reviewed by jerenkrantz, fielding, wrowe for httpd-2.0.
Code committed is identical.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.0.x@477376 13f79535-47bb-0310-9956-ffa450edef68