#1 Missing short protocol name crashes dicom2X

[Philip Cook]

The protocol lists should include a "short protocol name", which is used in the output. For example,

t1_ax_MPRAGE mprage

This tells the script to look for directories matching t1_ax_MPRAGE and to name output subject_timepoint_mprage_{t1ext}

However, if you don't specify the short name, the script can crash. It should have a sensible default value.