Updated version to 0.8.2
Catch errors in Stylus initialization as well and provide native stack trace

Helps with development.
Shorter error reports for syntax errors

No need to provide the Java strack trace when it's strictly a Stylus
parsing error.
Implemented the realpathSync function used in some parts of Stylus

Doesn't seem like we actually need it, it's always called inside
try/catch statements, but can't hurt and may have some non-obvious
meaning.
Finally: nice (and above all correct) error messages!!

Seems like it was an upstream issue:
https://github.com/LearnBoost/stylus/issues/1745
Code cleanup (comments, reduntant lines..)