Update the installer to fix overwriting of user's already installed

configuration or htdocs files. This is similar to how APACI now works.
For the configuration files, the @@...@@ tokens are expanded, and
the file called conf\*.conf.default. Then it is _copied_ to the
corresponding conf\*.conf _only if_ that file does not exist. If it
does exist, it displays a messagebox saying "Preserving file XXX", like
APACI. [PR#2118]

For the htdocs, the manuals are always installed into htdocs\manual(*)
However htdocs\index.html and htdocs\apache_pb.gif are not installed
if they already exist. So this will now not overwrite the user's
index.html file. [PR#2084 -- for Unix, but applied to Win32 as well]
Note: under APACI the manuals are not installed if htdocs exists. On
Win32 htdocs\manuals is installed. This is because we add a menu
item "Apache Documentation" which launches explorer to read the docs, so
we really want them installed.

(* if the installation type includes manuals, that is).

A couple of other fixes:

  - always create cgi-bin and htdocs directories, even if the
    manuals are not being installed

PR: 2118, 2084


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@81178 13f79535-47bb-0310-9956-ffa450edef68