[Homer-users] prune channels update

[David Boas]

Based on the discussion from the training session last week, I have 
updated the Prune Channels function (enPruneChannels) to take a range of 
source detector separations for deciding which channels to include in 
the processing. This is now in the developers version of homer.

I also made a small update to the hmrDeconvHRF_DriftSS function so that 
it now returns the correlation coefficient of the GLM fit to each 
channel of data. This result can be found in the nirs file in procResult.R

Note that other GLM functions are still in homer for historical reasons. 
hmrDeconvHRF_DriftSS supersedes all of them and contains all of their 
functionalities. At some point I will remove all of those other GLM 
functions since they are now superfluous.

Also, I added information to homer-fnirs.org/faq about creating the 
digpts.txt file.

David