Updated character matchers to be the same as the latest version of TurtleUtil.java
https://bitbucket.org/openrdf/sesame/src/95e3d88068941b1b65568b64c0b007251dc7df32/core/rio/turtle/src/main/java/org/openrdf/rio/turtle/TurtleUtil.java
Added support for escape characters appearing in pnames