[osg-submissions] Plugin DLL search order fix for Win32

[Luigi Calori]

Robert Osfield wrote:

>Hi Luigi,
>
>Well done on getting things working, it would be nice to roll this
>into the 2.1.8 dev release.  I guess it'd be worth getting some
>feedback from other engineers before merging though, perhaps posting
>the changes to osg-users would be appropriate.
>  
>
Sorry, Robert, the things are not working:
I did a Debug build ok, then during night I did a Release build and this 
morning I found it was not built.
The hack I used for renaming only .dll is not working in release mode, 
don' t know why. I' ll ask to CMake list
So hold back the merging.
At this point I do not think the whole layout can be done without either 
do  some copying  core dll in bin or  renaming the clashing examples / 
applications.
The copying is appended as a post_build command.
Unfortunately, because we have debug and release targets differentiated 
by "d" the straightforward copy command issues a non-fatal error in 
build. Either we don' t care or,
we use  a quite convoluted workaround .
I have started this route, using ModukeInstall but unfortunately, it is 
not used by OpenThreads (do not know why), so either duplicate code or 
wrap in a macro (is allowed in OpenThreads ?)

If you like to go the core dll copying route, the non-fatal error 
copying solution is ready to go. the other requires more time.
Let me know your preferences.

Luigi