Renamed isValid() > !isIllFormed(), stop() > setIllFormed(), context() >
valuePath()

Improved QSettingsWriter

Added generic bypass of unexpected items
Fixed QSettingsReader sequence/record
Moved stop to QAbstractValue (maybe not such a good idea as it is mostly
used to ensure well-formedness that is the responsibility of the fluent
interface)

performance, even write :(

Made unexpected value handling explicit (removed operator QValueEnd)

isErrorFiltered for later refactor & removal

QValueEnd() is useful to handle UnexpectedValue vs a value that can be
ignored using any/end

Refactored isErrorFiltered using a QVariant context() method

those that ought to be handled)

Simplify design by provising QCur with all QValue overloads instead of
relying on a trait (this allows to simplifying calls stacks for debug
and provide type sensitive error handling context too)

Added QValue::setIsVariant to automate suspend/resume, error reporting
and error recovery using tryAny()
Fixed QVal::any() that missed resumeErrorHandler
Fixed QCborReader::tryBind(quint64) that consumed negative integers
Fixed handleError(qBindUnexpectedValue) to be more consistent
Removed unused and untested move operations for some QAbstractValue
implementations

need to add QSize,QRect,QPoint to basic types)

performance cost (getting rid of some virtual should improve this)

QValueEnd

Fixed illegal QSeq<T_>() calls (outside QVal)

may be templated on QValueMode...

undesirable methods like value() that allowed to concatenate QValues in,
say, a JSON stream

moving it