Closes #21 - File loading in order * Reworked LoadFiles to smaller methods for readability (also re #10) and structure * Now determine expected load return before loading then load all "expected GameSystem" before "expected Race" * Make "can load as race/game system/army" methods public in interface Re #22 - Get errored file loading * Created FileLoadFailure class and made LoadFiles return a list of them Also * Some code cleanup * Change to DictionaryUtils calls