Patch 7.2.041

Patch 7.2.041
Problem:    In diff mode, when using two tabs, each with two diffed buffers,
            editing a buffer of the other tab messes up the diff.  (Matt
            Mzyzik)
Solution:   Only copy options from a window where the buffer was edited that
            doesn't have 'diff' set or is for the current tab page.
            Also fix that window options for a buffer are stored with the
            wrong window.
Files:      src/buffer.c, src/ex_cmds.c, src/ex_cmds2.c, src/ex_docmd.c,
            src/ex_getln.c, src/if_sniff.c, src/main.c, src/netbeans.c,
            src/normal.c, src/popupmnu.c, src/proto/buffer.pro,
            src/proto/ex_cmds.pro src/quickfix.c, src/window.c

git-svn-id: https://vim.svn.sourceforge.net/svnroot/vim/branches/vim7.2@1248 2a77ed30-b011-0410-a7ad-c7884a0aa172