What do you call superfluous filler words like 'So' 'Anyhow' 'Anyway'?

Examples:

Anyway, after that I went home and went to sleep.

Anyhow, do you want to go for a drink?

So then, I was chatting to this girl and...

Now, Bob was a nice guy, but socially inept.

Her cooking was, well, terrible.

These words are distinct from fillers like 'umm' and 'err' because they are often used intentionally in written, usually informal, English, such as writing expressing a conversational tone.

Insofar as the 'superfluous filler words' denote or relate to language used for general purposes of social interaction, rather than to convey information or ask questions, they are phatic.

http://www.oxforddictionaries.com/definition/english/phatic