consistent quoting

bash best practice for quoting is easy to remember: quote everything
Merge pull request #1 from rolandwalker/quoting

Fix quoting
protect against history expression expansion

for example: `!!` will be left as a literal string
Merge pull request #2 from rolandwalker/bash_safety_history_expressions

protect against history expression expansion
test $EUID instead of $UID

This is technically more correct in terms of the ability to
install macports. (Though in practice the user is unlikely to
encounter a scenario where $UID and $EUID differ.)
Merge pull request #3 from rolandwalker/euid

test $EUID instead of $UID
exit script if any command fails with error code

This setting is definitely best practice for scripting bash.
HOWEVER, unlike #2 this is not a simple safety rail.  It
may be that merging this causes the script to fail because
there are unaccounted errors.
Merge pull request #4 from rolandwalker/bash_safety_exit_codes

Better error catching
Follow-up on better error handling
Added self-update feature
Forgot to add end color code
Update the man pages
Merge branch 'master' into gh-pages
Merge branch 'gh-pages' of https://github.com/alebcay/cooler into gh-pages