[WIP] added forecast.io node

added the forecast.io node. Looking for feedback/improvements
Lets not get too picky here. It is actually a good practise in some languages to declare all variables to be used at the top of a function. Variables in javascript have function-level scope (ie a var in an if statement is visible outside of the if statement, unlike in Java where it is block-level scope).One of the things our jshint rules looks for is multiple definitions of the same var within a function - which is a no-no. When I find a variable name being reused, for example, two for-loops next to each other both using `i` as an index, I commonly put those var declarations at the top.