Forbid singleton types for integers whose type is platform-dependent.

Closes PR13501.
Add links to the Wiki from the Community page.
improve ->'s source location tracking

closes PR 13514
add long-missing space
Typo in error message
Changes to move all games to Racket from Mzscheme.

Signed-off-by: Patrick Mahoney <paddy.mahoney@gmail.com>
Misc code improvements, help text typo.
More code therapy.
Some shuffling of text, and a `-wiki' for all wiki links.
"PLT Scheme Inc" -> "PLT Design Inc"
Correct Help Desk Search so it handles keywords and hash-colon-keyword lexemes.

Closes PR 13470.
add increase/decrease font size menu items (ala browsers)
avoid a wrapper on callbacks that get stored in a weak table

This fixes a bug in DrRacket where by changing the font size
would cause the line numbers to encroach on the space allotted
to the main text of the definitions window (or, if the font size
is getting smaller, make a large gap)
racket/gui: fix some contracts in docs
fix problem with the initial continuation prompt

(Got it wrong in 2f7d4b5e.)

Closes PR 13494
Add tests for subtyping -poly. Closes PR13510.
covered a missing case in the oc-status state machine
Replace <wbr> and <span class='mywbr'> </span> with zero-width-space.

The zero width space is a more robust way to add place to line-wrap,
according to: http://www.quirksmode.org/oddsandends/wbr.html

Closes PR 13305.
Amend comment.
fix rendering of example in Guide

closes PR 13517