Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Move the Boolean and ReturnStatus stuff from sprite.h to util.h and
get rid of sprite.h.

Obtained from: DragonFlyBSD

Rework the directive parsing code. Instead of using a lot of strcmp()s
on every line that starts with a dot use a minimal perfect hash
function and a single strcmp() on the first word after the dot
to find out whether it is really a directive call and, if yes, which
one. Then directly dispatch to a handler function for that directive
(or fall through to the dependency handling code). This makes the
directive parse a little bit more strict about the syntax: the directive
word must be followed by a character that is not alphanumerical and not
an underline (making .undefFOO illegal); .endif and .else can only be
followed by comments.

Clean up include files and file including. Split nonints.h into pieces
that get included just where they are needed. All headers include the
headers that they need to compile (just with an empty .c file). Sort
includes alphabetically where apropriate and fix some duplicate commenting
for struct Job, struct GNode and struct Shell by removing one version and
inlining the comments into the structure declaration (the comments have been
somewhat outdated).

This patch does not contain functional changes (checked with md5).

Submitted by: Max Okumoto <okumoto@ucsd.edu>