Add ability to register res4d timeseries

This can be useful for removing confound information
(e.g. for functional connectivity analysis). The current version
is unfinished. The timeseries is not getting renamed properly
in the data sink, and I also have not determined whether this
is the right implementation. (Using a command-line switch means
there's no record of whether the timeseries that ends up in the
reg/ directory is pre- or post- model fit, but it doesn't make
sense to parameterize this at the experiment level.
Add ability to register res4d timeseries

This can be useful for removing confound information
(e.g. for functional connectivity analysis). The current version
is unfinished. The timeseries is not getting renamed properly
in the data sink, and I also have not determined whether this
is the right implementation. (Using a command-line switch means
there's no record of whether the timeseries that ends up in the
reg/ directory is pre- or post- model fit, but it doesn't make
sense to parameterize this at the experiment level.
Correct naming of registered res4d file
Fix merge conflicts
Allow evoked code to extract from res4d timeseries
Add mean func to timeseries registration
Add residual timeseries registration to release notes
PEP8
Merge pull request #53 from mwaskom/reg_res4d

Add residual timeseries registration.