The debug_mode enables:
 - reporting about unknown kernel options in the config,
 - showing all checks from all supported platforms,
 - verbose printing of ComplexOptChecks (OR, AND).

This fixes the false positive report about LDISC_AUTOLOAD for old kernels

Nice, like it :)

And move config_checklist to other globals by the way.

This option is now enabled by default in case of compiler support.

Refers to PR #31.

Thanks to @HacKurx for his work.

config check is finished: 'OK' - 74 / 'FAIL' - 49

config check is finished: 'OK' - 50 / 'FAIL' - 73

No need to support old stable versions

config check is finished: 'OK' - 44 / 'FAIL' - 79

config check is finished: 'OK' - 55 / 'FAIL' - 68

config check is finished: 'OK' - 36 / 'FAIL' - 87

config check is finished: 'OK' - 47 / 'FAIL' - 76

config check is finished: 'OK' - 87 / 'FAIL' - 36

config check is finished: 'OK' - 84 / 'FAIL' - 39

config check is finished: 'OK' - 52 / 'FAIL' - 71

config check is finished: 'OK' - 47 / 'FAIL' - 76

config check is finished: 'OK' - 54 / 'FAIL' - 69

PAGE_POISONING is a debugging feature.
It provides less erasing than INIT_ON_FREE_DEFAULT_ON.
Join these checks with OR giving preference to INIT_ON_FREE_DEFAULT_ON.

Thanks to @madaidan for the details.

Also drop my previous recommendations about CONFIG_PAGE_POISONING_NO_SANITY
and CONFIG_PAGE_POISONING_ZERO.

Thanks to @madaidan
Refers to #29