more close paren adjustment repairs
v5.3.2 installers info
Scribble: add 'grouper and 'hidden-number part style properties

Also, clean up documentation and implementation of 'unnumbered and
'hidden.
Scribble: add `scribble/book' and `scribble/report' languages

These languages set the default class for Latex rendering, and also
adjust Latex commands so that top-level sections are chapters, etc.
fix prototype when the C compiler has no "no inline" annotation
Scribble: fix docs on Latex commands for parts and part references
fix `raco link' test
work around C library bug in powl()
racket/date: change `current-date', add `date*->seconds'