[model] association between country and states and refactor method to find states by iso
[migration] change numcode with iso code
[spec/models] refactor to use iso instead of numcode
[seed] change states seed to use iso instead of numcode
[migration] remove unnecessery migration for states
[specs/model] add few specs for attr_accessible attributes
remove missing column headers from keymap
Merge pull request #174 from Genshin/refactor_state_country_assoc

Refactor state country assoc
Merge remote-tracking branch 'upstream/master' into develop
Merge remote-tracking branch 'tapalilov/kagetsukidevelop' into develop
small fixes + added apng