Change the name for the new rs_context parameter.

Change the reserved name for the new rs_context parameter to be "context".

Since there can be only one rs_context parameter, report an  error if the
name is incorrect.

Also use "special parameter" consistently in the error messages to help
our developers distinguish between regular and special parameters.

Finally, some refactoring to make the code more understandable.


Change-Id: I6f23dc5a8ba3659714ad1f7ba41836ff8b92d9ec
(cherry picked from commit 9764eb3be0f2dcaaefa62fddc9fbedf14784ae38)
18 files changed