I hear って everywhere, and in the case of っていう I heard it was a shortening of という. But in the case of things like questions, where does って come from, and what exactly does it mean?
It is a contraction on と, simple at that. It may be used with an omission (eg. くださいって＝くださいといいました。）but I am afraid you just have to accept it as this and get on with getting familiar with when it is used.