First Beta Build of GNOME Shell 3.18 Refines the System Status Menu

GNOME Shell 3.18 Beta 1 (technical version number is 3.17.90) refines the message list style, fixes a type-ahead behavior the compose and backspace keys, and refines the system status menu. Additionally, the changes of the caret and focus viewports are now automatically avoided during pointer movement, and the system modal dialogs have been updated to match the modal dialogs of the GTK+ toolkit. The code has been cleaned up, and various other small bugs where fixed.