Log Message:
Update to 2.5.1, provided by Lokesh Mandvekar on pkgsrc-users:

Fix segfault when loading "layout" with non-zero parameters.
This affected multi-region. stack() must be called after the region bars
are created.

Fix layout entry in man page.

Improve stacking for windows with multiple transients.

Fix hang in fullscreen layout when a window has multiple transients.

Fix focus_(prev|next) for windows with multiple transients.

Add a missing queue.h macro to Linux util.h.

Set stacking order when setting up a new status bar.
Fixes stacking issues that can arise on a randr screenchange event.

Fix segfault in fullscreen layout when a window with transient(s) unmap.

Add default maximize_toggle binding to man page.

Add clarification for the 'name' option to man page.

Remove stray new paragraph macro in man page.