'custom:{}' (a DynamicConfigSerializer with nothing set) hits EXPECT_KEY
with a '}' and returns TOK_ERROR, so loadSerial stops there and silently
drops every property after it. Nothing follows 'custom' in NodePrefs
today, so it goes unnoticed until you add one.
Also include stdlib.h, which Arduino.h was providing on-device but not
in the native test build.
mikecarper
Und3r_1337
Michael Graff
Scott Powell