NoteSeq does memory allocation and leaks memory on each step

[federicobond]

NoteSeq is performing memory allocations with new and overwriting the cells variable on each step of life, rotate, flip and shift. This has two consequences:

• Performing memory allocation is inherently costly, so it introduces more chances of audio tearing.
• Old memory from the previous cells value is not reclaimed so it leaks over time, ultimately consuming all available memory.

A potential solution to this is to continuously flip between two preallocated cells arrays.