Mutable Instruments Marbles firmware

Fixes and minor improvements - Fixed a bug causing spurious jumps in the DEJA VU loop playback position (occurring randomly, when DEJA VU is turned CCW), and another bug causing an unexpected change in the loop (occurring randomly, on average once every 37 hours) when DEJA VU is locked at 12 o'clock. Thanks to Tyler/float32 for finding these two! - Fixed a bug occurring when a buggy external clock source "stutters" by sending two rapid rising edges distant by a few ms at each clock tick. - Lowered the amount of hysteresis in the quantizers responsible for converting a voltage or knob position into discrete settings (eg: a clock divider ratio, or LENGTH). This makes the relationship between a voltage (or knob position) and a specific setting more consistent. - Increased the width of the "virtual notch" for the 14-step setting of the LENGTH knob. Implicit and explicit reset - If a clock pulse arrives after a long pause (3 seconds, or 4 times the interval between two clock ticks, whichever the longest), the module will reset all counters, dividers, patterns, and the step number of the relevant section (t or X). Provided DEJA VU is enabled and set at 12 o'clock, this gives a completely reproducible behavior at each restart of the clock. - Hold the t and X section mode buttons (labelled E and N in the manual) simultaneously to repurpose the JITTER and STEPS CV inputs as explicit reset inputs for the t and X sections. The corresponding LEDs blink temporarily for 2s when the repurposed reset inputs are enabled, and go off when they are disabled (which is the default setting). The JITTER CV input is repurposed as a reset input for the t section: a rising edge on this input will reset, on the next clock tick, the clock divider, the step counter in the DEJA VU loop and the position of the rhythmic pattern. [...]