Bad tone quality generated by the tone generator when floating point is disabled (thanks Olle Frimanson for the report)

[bennylp]

Issues with the tone generator:

• The sine approximation algorithm especially for the fixed point version is not good enough, causing aliasing frequencies to occur
• The volume perhaps can be made louder
• The volume is different between float and fixed point version
• The tonegen should attempt to create a full period of wave signal, slightly truncating or appending some samples as necessary.