sample-editor easy fade-in/out + loop fold

[coderofsalvation]

This adds 3 filters in the sample-editor:

1) fade in (alias for fade 0-100) 2) fade out (alias for fade 100-0) 3) loop fold (blend second half with first half of sample)

rationale: If you spend time with the sample-editor on a daily basis, then 1&2 cover 99% of the usecases (which makes the current custom fade-dialog a pita to work with). Loop fold is great to compress existing loops, or create loops from samples which have a fade-in + fade-out character (a pad or reverb-tail e.g.).

[coderofsalvation]

thx! already merged in v1.04