math/amath: Update to 1.8.2

[ultima]

Summary

• Updated to 1.8.2
• Update maintainer address
• Included new dist sites
• Stopped build in install stage
• Sorted Makefile, Uses section is before option section[1]. Option section was also sorted to comply with[1].

[1] https://www.freebsd.org/doc/en/books/porters-handbook/porting-samplem.html#porting-samplem-order

PR\: 220741
Sumitted by\: Carsten Larsen <[e-mail]> (maintainer)
Reviewed by\: lifanov (mentor), matthew (mentor)
Approved by\: lifanov (mentor), matthew (mentor)
Differential Revision\: https://reviews.freebsd.org/DXXXXX

Test Plan

portlint:
WARN: Makefile: for new port, make $FreeBSD$ tag in comment section empty, to make SVN happy.
0 fatal errors and 1 warning found.

poudriere:
103i386
103amd64
110i386
110amd64
12i386
12amd64

[lifanov]

Approved!