change link gnu_static to c++_static

bump lib version 2.0

bump version to 1.8

add webp bitmap cache strategy auto to reuse glide memory cache and b…

…ump vertion to 1.6

summary: optimize zjupure#39, support zjupure#38

release 1.4 for glide 4.9.0

release 1.4 for glide 4.9.0

fix zjupure#19, ignore the background from webp images and use transp…

…arent instead

summary: avoid animation flick when view background color not match with webp background color, use transparent all like fresco

release 1.0 to support WebpDrawableTransformation