Add the long double math functions recently added from FreeBSD to their related man pages

exp was present in v1
https://www.bell-labs.com/usr/dmr/www/man31.pdf

branches: 1.31.12; 1.31.14;
Fix sentence.

Remove comma after the last Nm entry.

branches: 1.29.12; 1.29.16;
proofreading

branches: 1.28.2; 1.28.8;
Remove rest of the NOTES and ERRORS and references to pow(3) family.

Split out the logarithm functions from the perplex exp(3). Also remove some
useless notes in the latter (namely, no one cares that financial calculations
were done on Hewlett-Packard HP-71B, or that there is a LN1() in Pascal).

Note that rest of the functions come from C99.

merge conflicting error sections.

Add exp2 and exp2m

Punctuation fixes, bump date for log2{,f}.

Add log2 and log2f from FreeBSD PR 83845

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22280, verified by myself.

Use
.In header.h
instead of
.Fd #include \*[Lt]header.h\*[Gt]
Much easier to read and write, and supported by groff for ages.
Okayed by ross.

New sentence, new line. From Robert Elz.

Punctuation nits, use standard headers, sort sections, remove Tahoe references.

Generate <>& symbolically.

Add single-precision versions of interfaces to their manual pages' NAME section
and install links as appropriate.

More trailing white space.

add LIBRARY section to man page

rcsid facism, WARNSify

Add missing standards conformance statements.

PR/3405: Krister Walfridsson: Various typos; since we compile with POSIX
libm, we should not xref matherr(3), and describe the errno settings.

infnan(3) no longer exists.

removed log2 from manpage, libm doesn't provide that function.

First cut at adding float versions of math functions to the manpages.

Beginning of changes needed for fdlibm

Fix spelling errors.

Fix formatting of SEE ALSO section.

Change RANGE to ERANGE.

New code from uunet.

Add RCS indentifiers.

branches: 1.1.1;
Initial revision