Draft: Enhancements (nonlin grid, hidpi)

There are few multiple enhancements:

1. Draw in device resolution in HiDPI scaling. Most useful in non-linear scale, where each pixel represents range of timestamps instead of single one. Though linear also looks good, however there are no ranges and I did not check if basic step is subdividable.
2. Fixed non-linear grid. In my approach - ticks are mapped logarithmically to linear timeline, then converted to x*1.04^x kind of space, using LambertW function implementation from https://github.com/DarkoVeberic/LambertW (there are two implementations, one is faster, but with limited range, so both are used).
3. Optimized geometric progression build, for constant with monotonically incremented power. When tested with dedicated example program, it showed 50x speedup. This seems to be more than reduced multiplications number (estimating ~7x for 256px wide sidebar).

Fixes: #33