Add flag to disable installing unmaintained & deprecated pprof.

Everyone should be using golang pprof from, but
distros still ship our perl version and not everyone is aware of
better pprof yet.

This is another step in completely dropping perl pprof. We still
default to installing it, but hopefully we'll be able to convince
distros to disable this soon.

We still install pprof under pprof-symbolize name because
stack traces symbolization depends on it, and because golang pprof
won't support this feature.

This is related to issue #1038.
4 files changed