[gate-cvs] (ian_roberts) Allow user control of behaviour for unmappable characters

[<no...@so...>]

Log Message:
-----------
Allow user control of behaviour for unmappable characters (closes #1366409).

Added a runtime parameter failOnUnmappableChar, which defaults to true, to
control the behaviour of the wrapper when it encounters a character that can't
be represented in the selected encoding.  When true, keep the old behaviour of
throwing an exception.  When false, replace the unmappable character with a ?
and keep going.

Modified Files:
--------------
    gate/plugins/TreeTagger:
        creole.xml
    gate/plugins/TreeTagger/src/gate/treetagger:
        TreeTagger.java