fix end-of-file-position for parse errors
put attribute classes just before their parents
rename "word" function to "item"
rename Item class to Word
rename Sentence to ItemGroup
rename "text" function to "structure"
rename Text class to Structure
rename Correspondence class to StructureGroup
[structureGroup in example pages
rename "structureGroup" to "translation" in input (and structure-group in output)
structure => block, in input and output
rename itemGroup (item-group) to line in input & output
data-group-id => data-line-id
rename classes StructureGroup,Structure, ItemGroup
move TestTokenReceiver to separate source file
update web examples for renaming changes