backport of Nanoc::CLI.after_setup functionality
revert commit to limit the changes made to nanoc 3.x
remove self. to make the diff smaller
backporting test for Nanoc::CLI.after_setup
Fix default stylesheet link
Merge pull request #411 from nanoc/fix/stylesheet-href

Fix default stylesheet link
Merge pull request #407 from barraq/feature/backport-cli-after_setup

Backport Nanoc::CLI.after_setup functionality from nanoc 4.0
Reset corrupted PStore
FileSystemUnified data source: added configurable dirs for items and layouts

    content_dir for items
    layouts_dir for layouts
Merge pull request #412 from gpakosz/filesystem_unified-prefixes

FileSystemUnified data source: added configurable dirs
Add docs badge to README
Merge pull request #415 from rrrene/patch-1

Add docs badge to README
Add workaround for Nokogiri modifying input on JRuby
Disable pygments.rb, rdiscount and redcarpet on JRuby
Document #parse
Remove useless doc assignment
Create Piper class, for piping from/to spawned processes
Implement input handling for Piper
Wait for stdout/stderr threads to end
Use Thread#join rather than #value