waveform: sharp thick lines for waves

[jimmac]

• mimic the aesthetic of Amberol for wave previews
• try not to render fuzzy

[jimmac]

Before: thin 1px lines with a chance of being rendered inbetween the pixel grid with anti-aliasing (==> fuzzy)

After: pixel perfect and more meaty.

[jimmac]

For consistency sake, Vocalis/Sound Recorder is getting the same treatment.

[vixalien]

Thank you!!