Add 24.4 support

Also tests rejeep/evm#48
Avoid .DEFAULT rule in Makefile

Instead, use a proper 'group' rule using the `VERSIONS' variable.  Also,
the use of `::' signals that the order doesn't matter at all; the
recipes will be executed in the order they appear in the Makefile.
Compress Makefile usage

Instead of using `make 24.1', use `make 1'.

Also, skip install if it is present already.
Ensure correct version is being tested

The `--use' option for `evm' seems to be ineffective on my machine.
This usage is (or should be) functionally equivalent; it links `emacs'
to the correct version in EVM.
Add rules to install evm; cask
Ensure Emacs uses hard tabs for this file
Ensure dependencies for this version are in place
Merge pull request #35 from vermiculus/24.4-testing

Add 24.4 support