Small README fixes
Use new melpa URLs
Require at least Emacs 23.3, since 23.1 is unusable

See #220
Enable aggressive-indent for lisps
Restore accidentally removed sanityinc/newline-at-end-of-line
Add LICENSE (FreeBSD)

Closes #221
Fix up disclaimer paragraph in LICENSE
Provide maybe-require-package: like require-package, but fails softly
Use maybe-require-package to avoid emacs 24 version checks
Remove init-marmalade, which I no longer use