Make NS_ and BS_ parser syntax slightly more flexible

[driftregion]

Hi, thanks for this fantastic library!
I had to tweak the parser's regular expressions to get it to munch a DBC I came across that uses spaces instead of a tab before NS_, as well as an extra space in BS_ lines:
https://github.com/nkirkby/dbcc/commit/5247f2a7bbb44d386c03764eab1950f3a2a5854d

I haven't been able to dig up a DBC specification, so I'm unsure if the DBC I'm parsing is incorrectly formatted.

[howerj]

Cool, just pushed a fix, which is what you put in your fork. Could you make a pull request next time?

Cheers for that! Let me know if there are any problems.

[driftregion]

Cool, just pushed a fix, which is what you put in your fork. Could you make a pull request next time?

certainly. thank you