Added wavetable mode to SinOsc

[nshaheed]

You can activate wavetable sinosc like this:

SinOsc s => dac;

1 => s.mode; // 0 is calling std::sin, 1 uses wavetable
eon => now;

On my m4 macbook pro I'm getting a roughly 20% increase in performance running 10,000 SinOscs in silent mode.

When running in real time I can get a roughly 12% increase in the number of SinOscs I can run before running into audio glitches (2210 -> 2480). I am not a optimization expert so I'm sure there's more performance that can be eeked out.

[nshaheed]

TODO: this test is failing in 01-basic/274-type-edge-cases.ck, this is because SinOsc is printing out .help() and that's changed. Need to update the expected output.