Clarify the sourcemap_uri parameter.
Strip out './' when looking up relative @imports.

This was causing JRuby to choke on templates in a jar importing each other.

Relevant Stack Overflow question: http://stackoverflow.com/questions/8236327/getting-file-not-found-error-running-sass-and-compass-as-jar-in-ant

Closes #583
Get rid of a debugging raise.
Keep track of the importer for each Range.
Support comments within @imports in SCSS.

Closes #591
Fix an exponential parsing bug.

Fixes #604
Merge branch 'stable'

Conflicts:
	doc-src/SASS_CHANGELOG.md
Remove an incorrect statement from a warning.
Remove an incorrect statement from a warning.
Remove on_updating_stylesheet.
Remove Sass::Plugin.options=.
Remove Sass::Script::Number::PRECISION.
Disallow cross-directive @extends wholesale.
Throw an error for failing @extends.
Improve test_import_comments_in_imports.
Fix a broken test.
Merge branch 'stable'
Bump VERSION to 3.2.4.
Merge branch 'stable'

Conflicts:
	VERSION
	doc-src/SASS_CHANGELOG.md
Allow importers to specify their custom public URLs for use in sourcemaps.