Cleaner CSV output for time/float4 and offset/score arrays

Previously, the output for these types was not parseable, bacause it contained
newlines.  In CSV files, newlines are used as a tuple delimiter.  The new
format uses a comma separated pairs, with the key and the value separated by a
colon.

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>