Change rainbow-mode upstream to elpa

- Add ac-html
- Add anchored-transpose
- Add rrc

fixes #2018.
No, `el-get` doesn't currently look at dependencies from headers, that's why that issue is still open.

Since `anchored-transpose` doesn't have any dependencies it's not strictly necessary to add a hand written recipe for it. But you have a reasonable point regarding the "bad quality". We can look at removing it along with similar recipes after we fix #1471.