In addition to adding `static' where possible:
- bin/date: Move `retval' into extern.h to make it visible to date.c.
- bin/ed: Move globally used variables into ed.h.
- sbin/camcontrol: Move `verbose' into camcontrol.h and fix shadow warnings.
- usr.bin/calendar: Remove unneeded variables.
- usr.bin/chat: Make `line' local instead of global.
- usr.bin/elfdump: Comment out unneeded function.
- usr.bin/rlogin: Use _Noreturn instead of __dead2.
- usr.bin/tset: Pull `Ospeed' into extern.h.
- usr.sbin/mfiutil: Put global variables in mfiutil.h.
- usr.sbin/pkg: Remove unused `os_corres'.
- usr.sbin/quotaon, usr.sbin/repquota: Remove unused `qfname'.
it respects PACKAGESITE, PACKAGEROOT, and a new environment variable ABI (if a user want to use a different API from the base one for its packages)
it has no man page on purpose to avoid hidding the pkg(8) man page from the pkgng package.
for now uses pkgbeta.FreeBSD.org as default mirror to find its package
it respects MK_PKGTOOLS
Approved by: des (mentor)
