Add sysconfdir.
Merge pull request #1418 from dcoutts/repl

A few cabal repl fixes
Link to imported source guide on Github, not to the older one
Merge pull request #1419 from Blaisorblade/patch-1

Link to imported source guide on Github, not to the older one
Update HACKING
Merge pull request #1415 from dcoutts/env-searchpath

Support for non-standard program search $PATH
Typo.
Whitespace.
Comment.
invokeSetupScript: use the passed-in argument everywhere.

The one from outer scope was used in some places before.
Remove a little bit of duplication.
Formatting.
Typo.
finalizePackageDescription: don't reverse the order of components.

Fixes #1424.
Rename 'extra-html-files' to 'extra-doc-files'.
Merge pull request #1427 from 23Skidoo/extra-haddock-files

Rename 'extra-html-files' to 'extra-doc-files'.
Merge pull request #1425 from 23Skidoo/issue-1424

Change the component load order for repl.
Use proper punctuation consistently.
Rename 'Distribution.Compat.*' to 'Distribution.Client.Compat.*'.

Helps to disambiguate Cabal's compat modules from cabal-install's.
80-col violations.