Use take start offset to set anacrusis

[Benjamin Klum]

Before, I considered treating item snap offset as anacrusis.

Following things make the take start offset a better candidate:

• Item snap offset is an item-wide thing. You can't determine the anacrusis on take level (take level makes more sense).
• The loop indicators when prolonging the item to the right make only sense if you adjust the take offset anyway. The loop border should be on the first beat, not on the start of the anacrusis.
• Item snap offset doesn't "survive" playrate changes. It refers to another position in the source when the playrate is changes. The anacrusis should stay the same!

[Benjamin Klum]

re #3 First draft anacrusis support

→ <<cset 2095e032163c>>

[Benjamin Klum]

re #3 When filling slot with selected item and detecting a take start offset that could be meant as an anacrusis, ask the user about it

→ <<cset d32ff4eb84d2>>

[Benjamin Klum]

re #3 Fix anacrusis timing when playrate != 1

→ <<cset 874bb097140b>>

[Benjamin Klum]

re #3 Ignore anacrusis if it doesn't fit within one measure

→ <<cset cbc1252f8811>>

[Benjamin Klum]

re #3 Fix anacrusis if it doesn't fit within one measure by completely removing the take start offset

→ <<cset e8658450f7ce>>

[Benjamin Klum]

re #3 Fix negative anacrusis when playing by completely removing the take start offset (negative anacrusis == take start offset > source length)

→ <<cset a8fddd30c1c8>>

[Benjamin Klum]

re #3 Get timing right when starting clip while anacrusis would already be playing and playrate != 0

→ <<cset 6f0c26789b6b>>

[Benjamin Klum]

re #3 Get timing right when starting clip after tempo change by modifying playrate before doing all the playrate-dependent calculations

→ <<cset 2a7e2852d8dd>>

[Benjamin Klum]

re #5 re #3 Show current values in section and anacrusis context menus even if not directly on beat

→ <<cset 7b9918535159>>

[Benjamin Klum]

Resolved in upcoming version 1.11.0