tools/dsa: Less cats
tools/dsa: Remove temporary file
tools/dsa: Refactor variable names
tools/dsa: Give columns a number if no header row

If we're not using headers, then we should use the row index as a column
name.
tools/dsa: Don't miss first row

If we're not using headers, then don't skip the first row when selecting
a column.
tools/dsa: Add some explanatory comments
tools/dsa: Add a main() function
tools/dsa: Clarify usage of colum()
tools/dsa: Split main() into smaller functions
tools/dsa: Fix percentage calculations
tools/dsa: Add a DEBUG mode

If executed with DEBUG=1, all executed commands will be shown. Usage:

   $ DEBUG=1 ./dsa ~/dataset.csv
tools/dsa: Check input arguments to perc()

If perc() is not given two inputs, print an error.
tools/dsa: Fail if input file not found
log: Notes for Wednesday
log/build: Use 'if' conditional not 'test'

Test exits with error code 1 if a condition is not met, so should not be
used to perform conditional actions as this will cause make to exit
with an error.
log: Fix typo
git: Ignore contents of priv/* directory