Re-implement isArray util method.
Re-implement isArray util method.

Actually I've stolen isArray from underscore.js library
roryf/Kalendae,scientiacloud/Kalendae,scientiacloud/Kalendae,IlanFrumer/Kalendae,pfiller/Kalendae,mirego/Kalendae,IlanFrumer/Kalendae,ChiperSoft/Kalendae,ChiperSoft/Kalendae,mirego/Kalendae,coreyzev/Kalendae,coreyzev/Kalendae