Spec for ignoring semi-colons at the end of blocks

Refs sass/libsass#595
Spec for preserving whitespaces surrounding selectors

Refs sass/libsass#552
Merge pull request #114 from mzgol/libsass-552

Spec for preserving whitespaces surrounding selectors
Merge pull request #112 from mzgol/libsass-595

Spec for ignoring semi-colons at the end of blocks
Spec for not trimming whitespaces inside selectors

Refs sass/libsass#593
Add spec for deep @extend specificity problems

Refs sass/libsass#592
Refs sass/sass#1495
Merge pull request #113 from mzgol/libsass-593

Spec for not trimming whitespaces inside selectors
Merge pull request #115 from mzgol/libsass-592

Add spec for deep @extend specificity problems