* Add r_io_map macros throughout code base
* Update string NULL-checking with renamed functions r_str_get() and r_str_getf()
* Change string NULL-checks throughout code base to use functions
* Add r_str_get_fail() to specify a custom string to return if NULL-check fails
* Mark JSON to be updated with PJ with "TODO PJ"
* Incidental style updates such as missing spaces