Merge pull request #54 from jeff1evesque/form_add_fields

#53: index.php, add 'Remove' buttons
#55: html_form.js, Properly append element after 'Remove' button
Merge pull request #56 from jeff1evesque/js_html_form

#55: html_form.js, Properly append element after 'Remove' button
#58: html_form.js, 'remove_callback' function skeleton
#58: html_form.js, trim 'element['button_class']', outline 'remove_callback'
#58: html_form.js, remove form elements, use object dot notation
#58: html_form.js, only remove elements when there is two or more
#58: html_form.js, remove form elements corresponding 'br'
#58: html_form.js, correctly remove elements corresponding 'br:last'
Merge pull request #59 from jeff1evesque/js_html_form

#58: Add 'delegation listener' for 'Remove' button
#60: Fix 'Linux Packages' Subsection
Merge pull request #61 from jeff1evesque/doc_linux_packages

#60: Fix 'Linux Packages' Subsection
#51: index.php, Add 'Training Type' datalist