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

gpu_cache: return CachedBy info

See merge request !139

Returns `CachedBy` enum for successful `cache_queued` calls.

Add fn `PositionedGlyph::set_position`

See merge request !137

Can be more convenient and in some cases faster.

```
name                                    control ns/iter  change ns/iter  
diff ns/iter  diff %  speedup 
cache::multi_font_population            2,410,117        2,339,255       
     -70,862  -2.94%   x 1.03 
cache_bad_cases::moving_text_thrashing  6,320,915        6,085,122       
    -235,793  -3.73%   x 1.04 
cache_bad_cases::resizing               4,269,353        4,219,784       
     -49,569  -1.16%   x 1.01
```

* glium -> 0.23

Edition 2018

See merge request redox-os/rusttype!136