Respect CSS "/" in Number#inspect.

Closes #1229
Fix a comment-parsing bug.

Closes #1226
Fix another comment-parsing bug.

Closes #1228
Fix a test failure on older Ruby versions.
Bump VERSION to 3.3.6.
Merge branch 'stable'

Conflicts:
	VERSION
	doc-src/SASS_CHANGELOG.md
Merge branch 'master' of https://github.com/nex3/sass into stable