Introduce CleanChars filter
Display the text if the regexp does not match
Use more tools of browser2 in dresdenwetter
Use more tools of browser2 in dresdenwetter (2/2)
Display GaugeMeasure when level is zero
CleanChars is now an option of CleanText
copy of NotLoaded and NotAvailable returns the same object
Revert "Rewrite the empty function according to the new NotLoaded"

This reverts commit 22606d961f52314e5a9c42324d6a40f8725bdae6.
Do not display the unit if the value is empty
Fix hints in not found error
Convert sachsen module to browser2
Do not set None to the id
consider select and textarea fields in forms
add Map, Date and Time filters
factorization to be more browser2 aware
Return NotAvailable if NotAvailable was given
If the regexp does not match, return NotAvailable
Rename Attr filter to Field
Introduce the new Attr filter
Use Attr in module sachsen