tiny tweaks to make the bash slightly more readable

setup/mail-dovecot.sh

@@ -88,11 +88,12 @@ sed -i "s/#port = 110/port = 0/" /etc/dovecot/conf.d/10-master.conf
 # this are minimal. But for good measure, let's go to 4 minutes to halve the
 # bandwidth and number of times the device's networking might be woken up.
 # The risk is that if the connection is silent for too long it might be reset
-# by a peer. See #129 and http://razor.occams.info/blog/2014/08/09/how-bad-is-imap-idle/.
+# by a peer. See [#129](https://github.com/mail-in-a-box/mailinabox/issues/129)
+# and [How bad is IMAP IDLE](http://razor.occams.info/blog/2014/08/09/how-bad-is-imap-idle/).
 tools/editconf.py /etc/dovecot/conf.d/20-imap.conf \
 	imap_idle_notify_interval="4 mins"
 
-# Set POP3 UIDL
+# Set POP3 UIDL.
 # UIDLs are used by POP3 clients to keep track of what messages they've downloaded.
 # For new POP3 servers, the easiest way to set up UIDLs is to use IMAP's UIDVALIDITY
 # and UID values, the default in Dovecot.

setup/system.sh

@@ -12,12 +12,9 @@ source setup/functions.sh # load our functions
 # text search plugin for (and by) dovecot, which is not available in
 # Ubuntu currently.
 #
-# Add that to the system's list of repositories using add-apt-repository.
-# But add-apt-repository may not be installed. If it's not available,
-# then install it. But we have to run apt-get update before we try to
-# install anything so the package index is up to date. After adding the
-# PPA, we have to run apt-get update *again* to load the PPA's index,
-# so this must precede the apt-get update line below.
+# So, first ensure add-apt-repository is installed, then use it to install
+# the [mail-in-a-box ppa](https://launchpad.net/~mail-in-a-box/+archive/ubuntu/ppa).
+
 
 if [ ! -f /usr/bin/add-apt-repository ]; then
 	echo "Installing add-apt-repository..."