Add ntriples-2013 alias to ntriples serializer
(raptor_uri_escaped_write): Added
Added escaped writing module to write Turtle/N-Triples terms

Added enum of bitflags raptor_escaped_write_bitflags that describe
the escaping wanted.

(raptor_string_escaped_write): Added

(raptor_string_python_write): Deprecated, now calls
raptor_string_escaped_write() with flags.

(raptor_term_escaped_write): Added.
Use raptor_string_escaped_write instead of raptor_string_python_write

(raptor_json_writer_quoted, raptor_json_serialize_avltree_visit,
raptor_string_ntriples_write,
raptor_turtle_writer_quoted_counted_string): Replace deprecated
function with new one

(raptor_turtle_writer_quoted_counted_string): Tidy code as well.
Use raptor_term_escaped_write instead of deprecated raptor_term_ntriples_write

(raptor_bnodeid_ntriples_write, raptor_statement_ntriples_write): Use
raptor_term_escaped_write instead of deprecated
raptor_term_ntriples_write
ws
Make raptor_turtle_is_legal_turtle_qname internal not static
(raptor_term_escaped_write): Encode uri not datatype uri
(raptor_string_escaped_write): Decode unicode chars
Remove spaces from test data URIs
(raptor_string_escaped_write): 0x7f is never written raw
Undeprecate raptor_statement_ntriples_write
Added turtle writer methods for writing uris and term

(raptor_turtle_writer_uri, raptor_turtle_writer_term): Added to
write URIs and terms.
Remove not needed RAPTOR_INTERNAL_API prefix
(raptor_turtle_writer_reference): Wraps raptor_uri_escaped_write
docs
(raptor_statement_print): Use raptor_uri_print
ADd docs warning about inefficiencies

(raptor_init_serializer_turtle, raptor_uri_turtle_write,
raptor_uri_to_turtle_counted_string, raptor_uri_to_turtle_string):
Add doc note warning they are inefficient - a turtle writer is made
and destroyed each time - and that a serializer is better.
Make raptor_uri_to_turtle_counted_string use a turtle writer.

(raptor_uri_to_turtle_counted_string): Use turtle writer and
raptor_turtle_writer_uri.  Add docs warning about inefficiency
(raptor_term_turtle_write): Wraps raptor_turtle_writer_term