A few minor documentation tweaks and improvements
Fix formatting typo in package description
Fix documentation of memory overheads
Mention ShortByteString in the package description

Also update a couple more copyright dates and fix a doc module name.
Move the other benchmarks into the separate cabal file

They also have the problem with recursive dependencies.
Declare all extensions in .hs files

Use Cabal-1.10 feature of other-extensions, so we declare which
extensions are used, but don't just apply all extensions to all
modules.
Bump version to 0.10.4.0
Tidy up a few more uses of extensions

Noticed by hvr.
Update tested-with list
Don't declare the Trustworthy & Unsafe extensions in the .cabal file

Not yet on the hackage extension list