Allow special reactive input element tag attributes !value and !checked.

[Tal500]

For reactive element <input />, we need to support the '!' syntax for 'value' and 'checked' attribute.

Usually, when the page is reloaded, the HTML input element value/check status is set to the value that was in the last time the page was displayed, and not to the initial value which specified in the 'value' and 'checked' attribute.

This case sometime is good (for exmplae for username field), but sometime is needed to be forcefully overridden.

If the user use the attrbiutes '!value' and '!checked' (starting with '!'), it should mean that we need to reset the value to the initial value in JS code while the page is loading.