- Copy stable/10@285827 to releng/10.2 in preparation for 10.2-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.2.
- Update default pkg(8) configuration to use the quarterly branch.[1]

Discussed with: re, portmgr [1]
Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r271651, r271719, r272138, r272457, r272845, r275476, r275518, r275614,
r275819, r276176, r278154, r278160, r278339, r279127, r279240, r279491,
r279493, r279856, r283032, r284423, r284426, r284427, r284428

Merge changes to libm from the past 9 months. This includes improvements
to the Bessel functions and adds the C99 function lgammal.

MFC r277948:
msun: use previously ignored "in" value.

This fixes evaluation of exceptional values in scalblnl().
While here, simplify the code as suggested by Bruce Evans.

Reported by: clang static analyzer

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

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

- Implement scalblnl.
- In scalbln and scalblnf, check the bounds of the second argument.
This is probably unnecessary, but strictly speaking, we should
report an error if someone tries to compute scalbln(x, INT_MAX + 1ll).

Add trivial implementations of scalbln() and scalblnf().
These routines are specified in C99 for the sake of
architectures where an int isn't big enough to represent
the full range of floating-point exponents. However,
even the 128-bit long double format has an exponent smaller
than 15 bits, so for all practical purposes, scalbln() and
scalblnf() are aliases for scalbn() and scalbnf(), respectively.