getLocale()/getPhrases() can return a falsy value.

[guillaumearm]

for v1.0

need #16

this will stop the progression :

• if getLocale() or getPhrases() return or resolve a falsy value, should return next(action)
• add 'previousLocale' as second parameter of getLocale() to determine if the locale have been changed.

about this behavior :

• need tests
• need doc

[JalilArfaoui]

I think it should return next(action), not return action

[guillaumearm]

yes, you're right.
i don't remember why I thought to do that when I wrote this issue :)

[guillaumearm]

I remember ! (for return action)

it's about SET_LANGUAGE action. we shouldn't propagate this action ( and only this action ) when return a falsy value.

but that's no longer news since #38. so don't worry about this ;-)