[Core] Fix random bug in updating settings via UI.

Sometimes the regex would fail, and it is easier to use
parse_ini_file() instead of reading in a string and applying
a regex, so redo this function a little.  It should also help
cleanup some people's messed-up files when the next setting
change is saved.
[UI] Add GPIO and Plugin log masks and make UI more understandable

UI is modified so that when you select 'all', all of the individual
checkboxes are automatically checked or unchecked.  When you select
'most', all but 'channeldata' are checked/unchecked.  If you
check an individual checkbox when 'all' or 'most' are checked,
then the 'all' or 'most' boxes are unchecked to signify that you
are no longer using the 'all' or 'most' masks.