When the constructor for the cos/sin table was changed from
number of bits to number of points all usages thoughout the
code should of been changed, but this was missed in RDFT and DCT.
Fixes Trac#10683.
This removes the large static tables from the binary (which saves 500K
to 1Mb of binary size) and replaced them with a class which generates
the required tables as needed in RAM. This has been tested with QDM2
and shows no obvious performance degredation and Memprof shows no
significant rise in RAM usage.