din: Update to 42

Changes since 41:

DIN Is Noise 42 @ Chennai, India
	Dedicated to Dad, Mr Narasimhan Sampath [06-10-1943 >> 16-04-2019]
	+++ Point Modulator on all curve editors, new for DIN42 +++
		+ modulate any point on any bezier curve along horizontal (ie X) and
			vertical (ie Y) axis over BPM
			+ eg., when done on a waveform, leads to timbral modulation, look @ the FFT :)
					+ try on shapeforms too!
					+ try on decays, delay feedback and volumes, pitch and range modulation
						curves etc etc!
		+ to modulate, click on the + button on the Point Modulator panel
			+ now pick a point on curve (any vertex or tangent) to modulate
				+ DIN draws a dotted line joining a state button to the point on curve
					+ nothing is modulating yet
				+ change X depth to modulate the point along horizontal axis over BPM
					+ the point should start moving along the horizontal
				+ change Y depth to modulate the point along vertical axis over BPM
				+ change X BPM and Y BPM to change the rate ie speed of modulation of the point
				+ when more than one point is modulating,
					+ click on None to deselect all modulating points
					+ click on a point's state button to change modulation params for just that point.
						+ use the X depth/BPM, Y depth/BPM spinners to change the params
					+ use All, None and Invert to select more than one state button and thus more than
						one point.
						+ use the X depth/BPM, Y depth/BPM spinners to change params for selected points
		+ press play button to toggle point modulation of selected points
		+ press kill button to kill point modulations of selected points
		+ point modulations are saved [and loaded] to [from] disk :)

	+++ Captures - mouse capture panel on all curve editors, new for DIN42 +++
		+ play, pause and kill captures
		+ To record a mouse capture, position mouse on the curve item
			that you want to assign the mouse capture, choose Menu > Mouse capture > Start,
			move mouse as you please and click or ESC to finish.
		+ To assign the mouse capture, choose Menu > Mouse capture > Assign and pick
			the curve item to assign the mouse capture.  You can assign the same mouse
			capture to other items by repeating the same.
		+ mouse capture is *not* saved to disk [maybe in a future release]

	+ Overlay pitch and volume distrubution on microtonal-keyboard:
		+ Menu > Misc > Overlay pitch distribution
		+ Menu > Misc > Overlay volume distribution
		+ Pixels Per Level
			+ more pixels, less acurate rendering of distribution but faster
			+ less pixels, more accurate rendering of distribution but slower
			+ Default is 5 pixels
	+ Mirror whole curve or curve vertex/tangent about Horizontal and Vertical axis
	+ Swap 2 curves [experimental, only works on editors with 2 curves]
	- removed Close button from Menu


(fox)