Support for passing/returning Structs by value. (#134)

* Added support for structs by value, fixed tests and example
* updated version, readme, changelog
* Added more tests
* Added struct return by value to native test
* Fix struct by value in nested typedefs

Author: mannprerak2

CHANGELOG.md

@@ -1,3 +1,6 @@
+# 2.0.0-dev.1
+- Added support for passing and returning struct by value in functions.
+
 # 2.0.0-dev.0
 - Added support for Nested structs.
 

README.md

@@ -377,8 +377,6 @@ class ArrayHelper_CXFileUniqueID_data_level0 {
 
 ## Limitations
 1. Multi OS support for types such as long. [Issue #7](https://github.com/dart-lang/ffigen/issues/7)
-2. Function's passing/returning structs by value are skipped. [Issue #3](https://github.com/dart-lang/ffigen/issues/3)
-3. Structs containing structs will have all their members removed. [Issue #4](https://github.com/dart-lang/ffigen/issues/4)
 
 ## Trying out examples
 1. `cd examples/<example_u_want_to_run>`, Run `pub get`.