- 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 r257770 r257818 r257823 r260066 r260067 r260089 r260145 r268587 r268588
r268589 r268590 r268593 r268597 r269758 r270845 r270847 r270893 r270932
r270947 r271147

Merge libm work by kargl, bde and das from the past few months.
Besides optimisations and small bug fixes this includes new implementations
for C99 functions expl, coshl, sinhl, tanhl, erfl and erfcl.

Approved by: re (kib)

* Makefile:
. Hook coshl, sinhl, and tanhl into libm.
. Create symbolic links for corresponding manpages.
. While here remove a nearby extraneous space.

* Symbol.map:
* src/math.h:
. Move coshl, sinhl, and tanhl to their proper locations.

* man/cosh.3:
* man/sinh.3:
* man/tanh.3:
. Update the manpages.

* src/e_cosh.c:
* src/e_sinh.c:
* src/s_tanh.c:
. Add weak reference for LBDL_MANT_DIG==53 targets.

* src/imprecise.c:
. Remove the coshl, sinhl, and tanhl kludge.

* src/e_coshl.c:
. ld80 and ld128 implementation of coshl().

* src/e_sinhl.c:
. ld80 and ld128 implementation of sinhl().

* src/s_tanhl.c:
. ld80 and ld128 implementation of tanhl().

Obtained from: bde (mostly), das and kargl