make sure to use 64bit if DFP/128bit not requested

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6338 4407c894-4637-0410-b4f5-ada5f102cad1
merge Decimal Float print and 128bit int printing to trunk

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6339 4407c894-4637-0410-b4f5-ada5f102cad1
merge metadata for dfp_internal.h

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6340 4407c894-4637-0410-b4f5-ada5f102cad1
web: make it clear that GCC [4.5.1; 4.7.x] is only supported for CRTv2.

Because of the formatting, it was possible to believe that GCC versions
from 4.5.1 to 4.7.x were supported for CRTv3 too.

Instead of mentionning CRTv2 and these GCC versions in two separate <p>
blocks, put them in the same so that it is clear this relates to v2.

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6341 4407c894-4637-0410-b4f5-ada5f102cad1
web: update source link to CRTv3.

It has been some time but the download page hadn't been updated to point to
the new CRT.

Also update the page to mention that winpthreads is in CRTv3 and that it
must be fetched from SVN for previous versions.

Since winpthreads is in the main download, remove the link to the
#source-winpthreads from the navigation bar on the left of the website.

Also sneak in a small formatting fix for yypkg.

git-svn-id: https://svn.code.sf.net/p/mingw-w64/code@6342 4407c894-4637-0410-b4f5-ada5f102cad1