Revert "User's guide (README)"

This reverts commit 3bb6b6c05c084f81dc830900a01072148bf78a83.
Revert "Default help page"

This reverts commit 53b8125b121eca8072dce21efeee57391bba32f0.
Revert "Default front page"

This reverts commit 65ef8a3c8f54f5c3c941bd06fa92f22ba4a40697.
Clean up cabal file.
Add CHANGELOG.md and README.md.

The extra-doc-files property requires cabal-version >= 1.18 (c.f.
http://coldwa.st/e/blog/2013-08-21-Cabal-1-18.html).  Bump this requirement
from 1.10.
Add homepage and bug-tracker to cabal file, linking to github.
Update tested-with version: GHC-7.8.3.
Bump version to 0.2.6.2 from 0.2.6.1.