Error when parse STDF contain GDR

[showjim]

I found there is an error, when parser GDR.
The reason is in class TextWriter. The method "text_format" is a static method without "self", but in GDR brantch "self.delimiter" is used and lead to the error.

[Joshhzhao]

same issue i found, i directly changed self.delimiter to "|".join.... to fix issue temproary, before that i also found the issue about VnMap = { 0: lambda header: self.inp.read(header, 1) ......}, system shows 1 to 2 positions but give 3 arguments.., i changed to 0: lambda header: self.inp.read(0), the issue fixed, but i am not clear real reason.

[matt-beyer]

This is the same issue as #17 ... for now I'm using previous release via pip install git+https://github.com/cmars/pystdf.git@966cd5b, and switching my import to AtdfWriter rather than TextWriter.