opentrack 2.3.0 release candidate 13

• Translation compensation got renamed to relative translation. Also, effect of each rotation axis on translation can be disabled, and each translation axis can be excluded from relative translation.
• Mapping snap got lowered to (1, 1) and (.5, .5) for rotation and translation respectively. We have tooltips so it's not a problem.
• Tracking stop won't reset unsaved dialog changes. Only closing a dialog without saving will reset unsaved changes.
• Tracking will try very hard to keep running at constant framerate (250 Hz). Previously it only adjusted based on the last delta.
• The Octopus now has larger resolution, and looks more correct when rolled.
• Trackers submitting rotation over +-180 will have it normalized.
• PT tracker had too small auto threshold point area. We forgot to multiply by Pi. Now the area is larger by 3.14.
• PT tracker finds point centers a bit more accurately.
• Some Accela settings had their maximum values reduced to prevent user confusion. They didn't make sense at these high values.
• Settings dialog in PT and Aruco won't show itself for A4 TECH cameras, in addition to PS3 Eye. The former crash when trying to open the dialog.
• All Rift versions now work without gimbal lock. It was only tested on 0.8.0 but the code is pretty much the same for all the versions.