Makefile.am: Added missing -lpthread for libca-table

The fifo module uses pthread_ functions for passing messages between readers
and writers.

Signed-off-by: Morten Hustveit <morten.hustveit@gmail.com>
Require that any row be one contiguous memory area

This makes it much easier to pass complete rows around, for sorting, merging or
other purposes.

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