btr_page_create(): Remove parameters "prev" and "next".  The pointers
to adjacent B-tree pages will be set in the caller before any user
records are inserted.

Remove the redo log entry type MLOG_ZIP_ROOT_RAISE, since
btr_root_raise_and_insert() will not defer modifications to
the compressed page.

btr_attach_half_pages(): Add parameter new_page_zip.