This will allow us to use better formats that preserve the entire
alpha channel.

Add a magical cursor framebuffer class for handling when you
want to render the cursor on the server side. Keeps the cursor
specific magic in one contained place.

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@589 3789f03b-4d11-0410-bbf8-ca57d06f2519

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/branches/merge-with-vnc-4.1.1@522 3789f03b-4d11-0410-bbf8-ca57d06f2519

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@2 3789f03b-4d11-0410-bbf8-ca57d06f2519