-replaced all PI references with M_PI version
-there is no need to do the angle-modulo in float, casting it to an integer does the same BUT it has to be cast to an `int` first, see comment.
* fixed the positioning of the download button
* fixed space after "Download the latest binary:" disapering after building
* fixed typo
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Co-authored-by: maxi4329 <maxi4329>
- `sin16_t() / cos16_t()` are faster and more accurate than fastled versions
- `sin_approx() / cos_approx()` are float wrappers for `sin16_t() / cos16_t()` and are accurate enough to replace `sinf()/cosf()`
- `atan2()` is used only in octopus to calculate center offset, new approximated version saves flash
- `tan(), atan(), asin(), acos(), floor(), fmod()` are used only for sunrise/sunset calculation, using wled_math version saves flash
- `beatsinx()` replacements are to make use of new `sin16_t()/sin8_t()` functions to reduce flash size
- Extensively tested surnise/sunset calculation: deviation is 1min. max
- Tested some of the relevant FX and found no visual difference: Julia, 2D Drift, Drift Rose, Ghost rider, Rotozoomer, Palette, Arc 1D expansion
- total flash savings: 7.4k
- changes to `setPixelColorXY` give an extra FPS, some checks and the loops are only done when needed, additional function call is still faster (force inlining it gives negligible speed boost but eats more flash)
- commented out the unused `boxBlur` function
- code size improvemnts (also faster) in `moveX()` and `moveY()` by only copying whats required and avoiding code duplications
- consolidated the `blur()` functions by enabling asymmetrical blur2D() to replace `blurRow` and `blurCol`
- compiler warning fixes (explicit unsigned casts)
- removing WS2812FX::setMode()
- removing WS2812FX::setColor()
- removing floating point in transition
- color handling modification in set.cpp
- replaced uint8_t with unsigned in function parameters
- inlined WS2812FX::isUpdating()
- (MAY BE BREAKING) alexa & smartnest update
* adding missing flash size flags that were lost between 0.14 and 0.15
(necessary if you don't flash using esptool)
* adding env:esp32dev_16M for 16MB flash (serg74 esp32-16M, twilightlord esp32 16M)
