Fix issue 335 - pspm_scr_pp

[teddychao]

Fixes #335.

Changes proposed in this pull request:

• Update pspm_scr_pp: users now can specify whether processed data and missing epochs are saved respectively.
• Update pspm_scr_pp_test: testing if processed data and missing epochs can be specifically saved.

[dominikbach]

github messes up the diff (not sure why), could you briefly say what has changed?

[teddychao]

github messes up the diff (not sure why), could you briefly say what has changed?

Hi Dom,

Sorry I did not state the modifications clearly before asking you to check.
For pspm_scr_pp, I only sorted the help text.
For pspm_scr_pp_test, I only make to code to verify if a channel is added when users want to add a channel to save the modified scr signal, in Line 57 of pspm_scr_pp_test.
I am a little confused about the issue because the code will save the modified scr signal when missing epochs are not saved. This is consistent to pspm_pupil_pp. I have contacted Carlos for further information about the issue.

Thanks.

[teddychao]

@dominikbach Hi Dom, may I know if you would suggest to expand the current data saving method to other related functions, e.g. pspm_pupil_pp? Users may prefer to save data files and missing epochs at the same time from other functions I assume, but I could be wrong.