cmd/ld: wrap long data lines in -a output
cmd/ld: wrap long data lines in -a output

Also move symbol names onto lines by themselves: some are very long.
Show relocations.

R=ken2
CC=golang-dev
https://codereview.appspot.com/7689043

pombredanne/go-deleteme,dsriram/golang,pombredanne/go-deleteme,dsriram/golang,apparentlymart/golang,apparentlymart/golang,tv42/old-go,pombredanne/go-deleteme,tv42/old-go,gnanderson/go,dsriram/golang,gnanderson/go,pombredanne/go-deleteme,gnanderson/go,dsriram/golang,tv42/old-go,tv42/old-go,dsriram/golang,pombredanne/go-deleteme,dsriram/golang,apparentlymart/golang,tv42/old-go,apparentlymart/golang,gnanderson/go,gnanderson/go,apparentlymart/golang,gnanderson/go,apparentlymart/golang,gnanderson/go,apparentlymart/golang,dsriram/golang,pombredanne/go-deleteme,pombredanne/go-deleteme,tv42/old-go,tv42/old-go