.gitconfig: Alias ls="ls-files"
ack 2.00b06 (git commit 04e8986)

Switch over to using Ack v2.0.

* .ackrc: Eliminate --text option which is obsolete in ack2.
* .ackrc: Change --type-set options to new-style --type-add options.
* .bashrc: Don't need to use ack-wrapper anymore, at least for now.