adding docs in the piki format.
Avoid use of discard-input. Fix #405.
Remove timeout from loop in ghc-sync-process

This fixes the possibility that ghc-process-running was left non-nil
after timeout.
Quit still can abort the loop.
Merge pull request #408 from iquiw/master

Remove timeout from loop in ghc-sync-process
Update extract module regexp for unicode quotes

GHC-7.8.x uses U+2018 and U+2019 for quotes.

Also do not call ghc-resolve-document-path if module cannot be extracted
in case of local functions.
Fixing a race (#405).
Yet another fix for #405.
Merge pull request #409 from iquiw/master

Update extract module regexp for unicode quotes
Add installation note about Nix
Wrap cleanupGhcModEnv in finally
Prefix ghc-mod tmpdirs with "ghc-mod"