rule-prechecker as web accessible
hsl slide editing works
update parsedValue with object, not string
CssSize object
right = right for TRBL
prenormalisation for 1 & 4 CSS Size values
FourCssSizes editor, parser & prenormaliser
when merging saved and updated values, only parse the saved value once
remove obsolete RegexValueFormat ValueFormatsParser BorderFormat
remove ObjectParserAndBuilder, check for match in parsers
remove ObjectParserAndBuilder defn, and minor refactorings
remove tracing