Encoder

• Improve the tradeoffs for the random access mode across presets MR-M13:
• Quality improvements across all presets and metrics ranging from 0.3% to 4.5% in BD-rate (!2129)
• Spacing between presets [M1-M6] has been adjusted to account for the tradeoff improvements achieved
• As a user guidance when comparing v1.7 vs v1.6 in a convexhull encoding setup:
• v1.7.0 M2 is now at similar quality levels as v1.6.0 M1 while being ~50% faster
• v1.7.0 M3 is now at similar quality levels as v1.6.0 M2 while being ~50% faster
• v1.7.0 M4 is now at similar quality levels as v1.6.0 M3 while being ~40% faster
• v1.7.0 M5 is now at similar quality levels as v1.6.0 M4 while being ~30% faster
• v1.7.0 M6 is now at similar quality levels as v1.6.0 M5 while being ~25% faster
• Added an experimental tune SSIM mode yielding ~3-4% additional SSIM BD-rate gains (!2109)

Build, cleanup and bug fixes

• Various cleanups and functional bug fixes
• Fix build conflict with libaom