Updated pandoc help parsing for available formats.

Textile format didn't work because extra text wasn't stripped.
Also strips '*' from 'pdf*'

If you look at the latest output from `pandoc -h` it has a trailing line that gives more info about exporting to pdf format in the form 
```
[text...]
```
This is now stripped out, as is the '*' from 'pdf*' in the list of formats.