* Add support for reflection access filter
* Improve documentation
* Fix compilation errors
* Relax handling for BLOCK_ALL when invoking default constructor
* Improve handling for inherited fields
* Fix accessible test failing for static fields
* Simplify ReflectiveTypeAdapterFactory field writing
* Fix GsonBuilder changes affecting created Gson instances
* Improve documentation
* Improve handling for IllegalAccessException
For Java < 9, AccessibleObject.canAccess is not available and therefore checks
might pass even if object is not accessible, causing IllegalAccessException
later.
* Fix incorrect GsonBuilder.addReflectionAccessFilter documentation