ERC: Scroll to bottom by default

[Deniz Dogan]

This has always bugged me and I keep forgetting how to set it, since
there are two variables that need to be changed. By default, ERC
buffers "scroll" just like other Emacs buffers, i.e. when point
reaches below the currently visible portion of the buffer (e.g. when a
new message arrives in an ERC buffer), it scrolls half a buffer
length.

Given the nature of IRC and IM protocols in general, I think most
people would want to enable scrolltobottom by default and set
erc-input-line-position to -1, to make it act like pretty much every
other IRC client out there.

What do people think about this proposal?

-- 
Deniz Dogan