[Libreoffice] Suggestion: Let's switch to using MSVC2010 on Windows for master

As those of you who care might have noticed, LibreOffice master doesn't build on Windows currently 
because of problems with the ICU 4.6 we now want to use. ICU 4.6 comes with prioject files for 
Visual Studio 2010, that the existing Perl script (icu/createmak.pl) doesn't understand. (It worked 
with the VS2008 project files the oldr ICU version included.) Instead of wrestling with that, I 
suggest we just switch to VS2010 as the only supported compiler for Windows.

I think most of the work to support VS2010 has already been done (thanks, jcorrius), so all that is 
needed might be to just change oowintool to only look for VS2010. And then modify the ICU VS2010 
projects to build ICU the way we want, and fix up the ICU makefilery so that it runs msbuild on the 
solution file instead of dmake on (now no longer generated) makefiles.

Opinions?

--tml