f_contactline.py: Option to output multiple variables per cell

f_contactline.py: Separate data collection and output

f_contactline.py: Option to output multiple variables per cell

f_contactline.py: Separate data collection and output

f_contactline.py: Add averaging of data between multiple frames and more data types

f_contactline.py: Add averaging of data between multiple frames and more data types

f_contactline.py: Range of positional header given if average

f_contactline.py: Add option to subtract contact line velocity