Merge: New `deprecated` annotation
The `deprecated` annotation is used on methods to produce warnings when called in a non-deprecated method.
Instead of a simple Boolean flag, deprecation is a rich model information structure that can contains some documentation, and later be extended (eg. version information, suggested substitution, etc.).
Example:
~~~
class A
# standard documentation
fun foo is
# doc for the deprecation
deprecated
do
stuff
end
end
~~~
Migration of the existing code to use `deprecated`will done in a future PR, once #719 is merged to avoid conflicts.
nitdoc need also to be extended and presents deprecation information. (see #640)
Since the deprecation documentation is autonomous, it could be displayed specifically (eg. in a colored box)
Pull-Request: #723
Reviewed-by: Alexandre Terrasa <alexandre@moz-code.org>