Update: iki_read and iki_write.

Update: iki_read and iki_write.

Make sure the private header files use "IKI" in the comments and not "FSS".

Switch ove to using F_status_is_error_not() instead of F_status_is_fine().

Make sure iki_write actually uses the stream write.

Fix verbiage of "content" to "data" to avoid potential misunderstandings that this is referring to a "content" as defined by the IKI syntax.

Fix some cases where f_type_error was still being used instead of the data.error.to.stream.

Rename the variable "input" to "pipe" to be more explicit.