* Add full debug builds for all tests
In order to ensure the -DEBUG builds don't fail with checked-in code, add
two jobs which build even/odd with full debug flags to Travis.
Fixes#5143
* Add in dump of platform.txt to verify build options
* Fix BASH comparison of strings
* Fix debug-mode compile error in ESP8266AVRISP
* Add -Wextra to CI (matches IDE "All" warnings)