Added REST category and methods, you can now make POST/GET/PUT requests
working image caching
Merge remote-tracking branch 'origin/feature/rest' into feature/image-cache

Conflicts:
	Sample/src/main/java/com/cesarferreira/quickutils/sample/activities/MainActivity.java
	library/src/main/java/quickutils/core/categories/string.java
No need to initialize the image caching library
Merge branch 'feature/image-cache' into develop
Merge remote-tracking branch 'origin/develop'