Release icewm-3.0.0

Add support for tabbed windows (see icewm manpage).
Add "ignoreOverrideRedirect" winoption.
Hide taskbar with icesh -T hide.
Print a message if icewmbg encounters an image loading failure.
Add override and focusmodel commands to icesh.
Fix setWorkspace for issue bbidulock/icewm#667.
Improvements to icewm-menu-xrandr.
Clarify the icewmbg manpage about one image per workspace.
Updated translations: Macedonian and Swedish.

shasum icewm-3.0.0.tar.lz 915f556e08f0b97974ba9c4e8f99bb1eb7f62ac0

Note bug #93.