Update sysadmin_tools.rst

adding byobu usage
line length, description

lines wrapped at 80 chars, added short description about Byobu and why
you should use it
A few minor things before getting into ssh stuff.

* Add mention that one's environment can dictate the tools one uses.

* Small blurb about iTerm 2.

* Fix 'previous' typo; should've been 'precious'.
interstitial ssh examples
Add a conventions document.

This will contain the style guide (once it's written) and presently
contains the beginnings of a standard example network. The diagram still
needs some work, but all of the important machines are present.
Try to explain a littl about crisis management.

Just an incomplete first draft. Needs more detail.
Expand the crisis response section.

Some words abuot how important procdures are for dealing with a crisis.
This is not the place to describe how to create a procedure (that looks
like it belongs in the Business Continuity Planning section under
Disaster Recovery), but it definitely is the place to describe how
useful they are for responding to disasters.
Merge branch 'master' into topic/apeiron/sysadmin-tools-ssh
More ssh usecases; explain all of this is secure

I use each one of these, except for -R, every day. The one time I needed
-R it totally saved the day. Make sure the next generation knows what
tools it has.
Update sysadmin_tools.rst

firmed up descriptions in byobu section
typo
Merge pull request #100 from yoniYalovitsky/patch-1

minor typo
don't use aptitude by default

aptitude is not installed by default, so we shouldn't use it by
default in our documentation. (Especially since I don't see an
`apt-get aptitude` preceding it ;)
Merge pull request #101 from igalic/aptitude

don't use aptitude by default
Expand on shell portability concerns

- Explain the difference between /bin/bash, /bin/sh, and /usr/bin/env bash when specifying an interpreter for a shell script.
Wrap string literals per review comments,
Explain what the hashbang is and why it's important
Make bash manual a link, rather than have the link floating off in space.
Merge pull request #84 from inuse/patch-1

Update sysadmin_tools.rst
Import netbooting content, fix code-block