searches for word positions at end of RC and right after RC, as well as MX equivalents in visual dataset.  some bugs left
updated (and checked) script.
RCend, RCafter with matching MXend MXafter are found from dataset
assumes that current iteration across sentence length is sufficient to find a pseudo-match (if perfect match) fails.
added RCendafter vs. MXendafter contrast
Merge branch 'master' of github.com:schoffelen/MOUS
added RCendvsafter contrast. Current output is RCend, RCafter, MXend, MXafter. Considering whether to subtract with RC and MX conditions, and only returning
RCend-after  and  MXend-after.