Allow Importer objects to be placed onto the load path using add_import_path.

Closes #392.
Make Pathname objects work with add_import_path
Add a -I option to the global options so that you can add sass import paths via the CLI. Closes #375.
Better description for the --force option.
Update changelog.
Update docs for reset-baseline() in vertical_rhythm partial.
Iterate on the doc changes for the reset-baseline mixin
lock down nanoc because newer versions cause issues.
Remove unused -o-border-radius and -ms-border-radius
Merge pull request #808 from joschka/remove-unused-border-radii

Remove unused -o-border-radius and -ms-border-radius
Link to sass reference documentation fixed.
Fixes the sprite Magic Selectors.
Merge pull request #820 from piouPiouM/fix-sprite_magic_selector

Fixed the sprite Magic Selectors
Merge pull request #815 from bukhamseen/patch-1

Link to sass reference documentation fixed.
Minor cleanup of comment typos and sentence structure in transform.

The auto-generated docs don't preserve all of the whitespace, so the resulting output on compass-style.org benefits from punctuation.
Remove unnecessary vendor prefixes in border-radius
Remove unnecessary -o prefix for column
update documentation for appearance module
update -webkit-appearance link
final official link to webkit appearance values