Set csv field_size_limit to sys.maxsize

To proactively address TabViewer/tabview#150

Author: saulpw

visidata/loaders/csv.py

@@ -7,6 +7,7 @@
 option('csv_quotechar', '"', 'quotechar passed to csv.reader')
 option('csv_skipinitialspace', True, 'skipinitialspace passed to csv.reader')
 
+csv.field_size_limit(sys.maxsize)
 
 def open_csv(p):
     vs = Sheet(p.name, p)