devdraw: fix mouse warping with multi-monitor on OS X R=rsc CC=plan9port.codebot http://codereview.appspot.com/5748043

Devdraw now waits for the image: this means that there is no more blank image when toggling fullscreen, when unminimizing, or at startup; this also means that we can live resize, but we only enable live resizing with Page, because it seems useless for other apps, and Acme and Sam bug with it. The tradeoff is that bottom corners are sometimes automatically rounded. There is a way to prevent the rounding here: http://parmanoir.com/Custom_NSThemeFrame but this would obfuscate the code. Instead, we make sure that the corners are always rounded. Closing the window while its content is updated causes an exception, without this patch. This seems to happen regularly with stats(1). This patch avoids a possible deadlock at startup, which I never experienced. If I recollect right, there is little chance that this happens on a multi-core CPU. Minimizing now activates next app in line, and Devdraw now stops drawing while minimized. R=rsc CC=plan9port.codebot http://codereview.appspot.com/5499043

devdraw: fix winsize (-W) on OS X R=rsc CC=plan9port.codebot http://codereview.appspot.com/5749043

devdraw: fix fullscreen on Lion Now, if you full-screen an app running on a secondary screen, it only takes over that monitor. It does not cause the primary screen to disappear. Code by David Jeannot. R=djeannot24 http://codereview.appspot.com/5708046

devdraw: enable gestures on OS X Remove swipe gestures. Keep only 2-finger pinching and 3-finger tapping. R=rsc CC=plan9port.codebot http://codereview.appspot.com/5498094

devdraw: make OS X resizer unobtrusive R=rsc CC=plan9port.codebot http://codereview.appspot.com/5558051

devdraw: on OS X, add menu items "hide" and "plumb devdraw(1)" R=rsc CC=plan9port.codebot http://codereview.appspot.com/5505092

devdraw: OS X: neutralize menu and Dock bugs in fullscreen mode Previously, the menu bar has been set to hidden instead of autohidden in fullscreen mode, because it appeared too easily. Occasionally however, it still appears. This patch makes sure it won't. With OS X Lion's fullscreen, the Dock is autohidden, but sometimes remains hidden. This bug comes with visual menu bar bugs during space transition and when exiting fullscreen. Those bugs happen after each Devdraw's activation, for example. This patch neutralizes them. R=rsc CC=plan9port.codebot http://codereview.appspot.com/5502091

devdraw: fix handling of compose key on OS X This implementation is simpler to understand. It removes conflicts with other modifiers and with the virtual buttons. Pressing alt during a sequence now cancels it correctly. R=rsc CC=plan9port.codebot http://codereview.appspot.com/5507049

cocoa devdraw: activation on receiving Ttop messages (The new variable "willactivate" is in the input structure "in", which is illogical. But this structure will soon be renamed "app". I postpone the renaming to avoid conflicts with simultaneous Codereview issues.) R=rsc CC=plan9port.codebot http://codereview.appspot.com/5504102

devdraw: OS X dead key support R=rsc CC=plan9port.codebot http://codereview.appspot.com/5503086

Cocoa Devdraw: cursor fix R=rsc CC=plan9port.codebot http://codereview.appspot.com/5356050

Cocoa Devdraw: cursor, menu bar, old fs, activation R=rsc CC=plan9port.codebot http://codereview.appspot.com/5318054

devdraw: cocoa fixes, bigarrow support (thanks Marius Eriksen)

devdraw: more fixes (thanks David Jeannot)