Remove out of date OC docs and replace with pointer to the OC package.
improve GC handling of out-of-memory

There's a point in attempting to allocate a new large page
where it makes sense to GC and try again.
Mac OS X: incorporate Pango repair for Yosemite

Pango 1.36.6 fixes the problem, so update native libraries
and the Coretext patch.
racket/gui gtk: workaround problem with async IBus input method

Affects Ubuntu 13.10 and 14.04, especially with multiple processors.
ffi/unsafe/objc: fix `objc-is-a?` to recognize subclass instances

This repair turns out to matter for Mac OS X 10.10, where creating
a list box in a frame somehow makes the frame an instance of a
subclass (that implements notifications of some sort, I think).
That subclassing broke an `(objc-is-a? ... RacketWindow)` test to
recognize windows that belong to a particular eventspace.
Added fllog2near
Added fast-flfsa/error and flfsa/error (fused square-and-add)
Altered `keymap%` to not claim to handle key events that it doesn't

Previously, `keymap%` would return #t for all shift, ctrl, and key release
events. DrRacket's editors would then not handle those events (correctly,
as they shouldn't handle already-handled events), meaning that the events
weren't sent to any snips.
racket/gui cocoa: adjust control font for 10.10
Add `get-all-pkg-scopes`.
Add `raco pkg archive-pkgs`.