[pdal] reader text file

[Jed Frechette]

+1 for a text file reader. As much as I hate them, dealing with text 
files is one of the main things that keeps me from using PDAL as much as 
I would like.

For the interface it seems like just mirroring the writers.text Options 
would be a good start. On top of that being able to skip a certain 
number of header lines and set a spatialreference would also be great.

Thanks,

-- 
Jed Frechette