Implement Support for no_std

See merge request !145

Christopher Serr authored Sep 05, 2019 and Alex Butler committed Sep 05, 2019

This allows using rusttype on no_std targets by disabling the `std`
feature that is enabled by default and activating the `libm-math`
feature. On most targets you still want to keep the `has-atomics`
feature active, as that specifies that the target is capable of
supporting atomics, which only some embedded devices do not support.

Move tests, examples & benches into ./dev

See merge request !146

* Remove unicode-normalization
* Update CI & readme

Disable multithread dependencies on wasm32

See merge request !143

FIX: align_4x4 implementation

See merge request !142

fix align_4x4 implementation incorrectly causing a
change in UV coordinates

improve align_4x4 test to fail if the
UV coordiantes change when align_4x4 is enabled

add CacheBuilder.align_4x4 option

See merge request !141

If your backend requires texture updates to be aligned to 4x4 texel
boundaries (e.g. WebGL), this should be set to `true`.

GlyphIter and LayoutIter keeps the lifetime of the font data

See merge request !140