Notification of string changes

Author: David Mudrák
MDL-69772 admin: Better validation for the allcountrycodes setting
The patch introduces a new admin_setting field type that can be used for
specifying comma separated list of countries. The field has inbuilt
validation so that only valid country codes can be inserted.


http://git.moodle.org/gw?p=moodle.git;a=commit;h=47fe02cbea1879192480324e21d1bcbe2dd2bd7e
http://github.com/moodle/moodle/commit/47fe02cbea1879192480324e21d1bcbe2dd2bd7e

+ 3.8 en [invalidcountrycode,core_error]