Add test for parsing error in SassScript Maps implementation -- libsass PR 481
Add test for multiple key removal functionality in map-remove(), as per Sass 3.4.x
Add test for multi-assignment in `@each`
rename issue 481 dir to issue 509
enable basic test 51: trailing commas
Merge pull request #58 from lunelson/master

Tests for nested maps, map-remove, multi-assign...