Remove some deprecated functions from ApiBase
* ApiBase::addTokenProperties() was removed (deprecated since 1.24).
* ApiBase::getFinalPossibleErrors() was removed (deprecated since 1.24).
* ApiBase::getFinalResultProperties() was removed (deprecated since 1.24).
* ApiBase::getRequireAtLeastOneParameterErrorMessages() was removed (deprecated since 1.24).
* ApiBase::getPossibleErrors() was removed (deprecated since 1.24).
* ApiBase::getRequireMaxOneParameterErrorMessages() was removed (deprecated since 1.24).
* ApiBase::getRequireOnlyOneParameterErrorMessages() was removed (deprecated since 1.24).
* ApiBase::getResultProperties() was removed (deprecated since 1.24).
* ApiBase::getTitleOrPageIdErrorMessage() was removed (deprecated since 1.24).
* ApiBase::parseErrors() was removed (deprecated since 1.24).
* Remove related constants ApiBase::PROP_ROOT, ApiBase::PROP_LIST,
ApiBase::PROP_TYPE, ApiBase::PROP_NULLABLE.
Patches were submitted for remaining uses in Gerrit extensions.
Change-Id: Idea70300874258fbcb9deef6504eb55f2ebe8d6c