Improved OS Checking and Formatting adminHelper.sh

Two changes to adminHelper.sh

Improved OS checking, largely taken from testOSRequirements.sh. Also,
improved consistency of whitespace formatting for ease of reading code.
Merge branch 'formatting-adminHelper.sh'
Execute adminHelper.sh with Bash

Commit fixes jamf/NetSUS#29. Execute adminHelper.sh with /bin/bash
rather than /bin/sh.
Merge branch 'bug-29'
Check on index.sucatalog File Date

Commit fixes jamf/NetSUS#26. Date being grabbed is for
index.sucatalog.apple, which is the last time Apple modified this file,
not the last sync.
Error Checking for Last Sync

Rather than displaying an error in the browser, display ‘Never’ if no
sync detected.
Revert "Error Checking for Last Sync"

This reverts commit 96183c52a5de7b0aa73bf23b69a8bbf51b437640.
Error Checking for Last Sync

Don’t display a shell error if no last sync. Display ‘Never’
Merge branch 'bug-26'
Install netatalk Dependencies

Fixes jamf/NetSUS#23. Installs avahi-daemon dependencies for netatalk.
Merge branch 'bug-23'
Added Support for Ubuntu 14.04

Added support to detect Ubuntu 14.04. Most significant changes to
apache.
Merge branch 'feature-ubuntu14.04'