Ability to make doxygen only index specified modules

Hi all, 

I’ve been running make docs on my local system, but I’ve noticed it takes a fair amount of time to 
index all modules, when all I wanted to index was the vcl module. 

I’ve made a small change to solenv/bin/mkdocs.sh that is entirely transparent to the existing 
processes. All I’ve done is add a test of the environment variable $INPUT_PROJECTS, if this exists 
hen use the list of modules specified. If it doesn't exist then the script runs as normal and 
processes all modules.

The change can be seen here on cgit:

http://cgit.freedesktop.org/libreoffice/core/commit/?id=cfcef8c99908a781c1d5b4153f4fa9fca69d4351

So basically, if you want to index vcl and svtools, then you would do the following:

chris@libreoffice-ia64:~/repos/libreoffice$ export INPUT_PROJECTS="vcl svtools"
chris@libreoffice-ia64:~/repos/libreoffice$ make docs
chris@libreoffice-ia64:~/repos/libreoffice$ unset INPUT_PROJECTS

Hope this is helpful!

Actually, I believe that the make file has help text, I’m thinking of adding it in there once I 
remember where the text is stored…

Chris