nitg: Added C stack trace when encountering an error

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
nitg: Added typing test on new for non-concrete classes + unit tests for new abstract and interface.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
Merge remote-tracking branch 'lucas/compiler_abstract_fix'
Merge remote-tracking branch 'lucas/unwind_integration'
Merge remote-tracking branch 'alexis/various-fixes'
src: delete old ffi and native_interface code

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
tests: remove native interface tests

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
model: rta uses its visitor only to visit FFI extern methods

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
grammar: use . instead of :: in FFI imports

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
grammar: change FFI declaration format of casts

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
nitg: intro the nitni module

Offers services defining the tailored API used by the FFI.

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
nitg: intro the common_ffi module and support for the C language

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
nitg: intro the compiler_ffi module to support the FFI in nitg

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
nitg-g: support cast between subtypes of Pointer

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
nitg: activate support for the FFI in nitg

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
nitg: detect if a compiler supports the FFI

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
c_src: update with support for new FFI

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
tests: update FFI tests to latest spec

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib: update standard library to latest FFI spec

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib: update the json module to latest FFI spec

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>