Fix missing hex_val conversions
Fix missing hex_val conversions

In the mosaic squares pattern, vals were being sent as strings from
the hash without being converted to numeric form first. When val > 9,
for examples, opacity incorrectly ends up at its minimum value 37.5%
of the time.

webbab/geo_pattern,webbab/geo_pattern,jasonlong/geo_pattern,tarebyte/geo_pattern,jasonlong/geo_pattern,tarebyte/geo_pattern