Fix parent selector resolutions with newlines + commas.

Closes #1140
Merge branch 'stable'

Conflicts:
	doc-src/SASS_CHANGELOG.md
	lib/sass/selector/simple_sequence.rb
Properly set force_polling for recent Listen versions.

Closes #1132
Allow any listen version before 3.0.0.
Add a dependency on Rake.

This is necessary for mkrf_conf to work.

Closes #1130