fix PLTSTRINGCONSTANTS printouts

also, Rackety
Fix TR reference discussion of filters

Thanks to Anthony Carrico
add a string-constant for out memory during background expansion
adjust drracket's online expansion to terminate out-of-memory expansion attempts
Fix unannotated defines with bad number of values
unbreak macro stepper

bug introduced in d495f74648
updated history
fixed docs for integer-sqrt, as reported on users
fixed docs for integer-sqrt, as reported on users, take 2
Fix the TR fix in efd482c30ff80f

My fix had just patched over a contract violation in a different
function. This commit fixes the root of the problem.
Unbreak the build on FreeBSD 10.

isnan expands into a use of a function called _Generic.

Tell xform not to worry about it.
fix `peek` implementation in R6RS input ports

The peek operation must not block, otherwise the port behaves
badly for `sync`.

Based on a bug report from Brett Stahlman.
fix "r6rs-test" dependency declaration
redex: favor recursive rules above the bound
Add more typed bindings for framework and for GUI
Fix type for text:line-numbers-mixin
redex: fix recursive calls to use premises clauses
avoid stack-overflow in scheduler-triggered foreign calls

While a foreigh call is normally guarded by a check on the amount
of available stack space, a callbacks triggered by the
scheduler will first put Racket in no-stack-overflow mode, and
then it's too late to check stack space before making further
foreign calls. With Cocoa, there's some chance that the process
will run out of space. Avoid the mismatch by checking the stack
availability at the start of a scheduler iteration.
Change RacketCon title and abstract.
RacketCon Logistics info.