Bump VERSION to 3.4.0.alpha.
Revert "Remove support for script &."

This reverts commit cbd07dac56028e2216972e1c009d7bf24027b588.

Conflicts:
	doc-src/SASS_CHANGELOG.md
	lib/sass/script/lexer.rb
Add support for all the Values and Units level 3 units.

This also pre-computes more unit conversions, so it should make
arithmetic a bit faster.

Closes #311
Preserve the user's color format.
Make existing tests work with preserved color representation.
Add explicit tests for preserved color representation.

This also preserves the original representation in compressed mode if
it's the same size as the smallest representation.
Add a CHANGELOG entry for color representation preservation.
Merge branch 'preserve-color-format' into bleeding-edge

Closes #363
Support ids in SassScript.

To be completely correct in our implementation, we would need to
ensure that no color that is also a valid id changes its
representation, even in compressed mode. However, this would
negatively affect all users of Sass for the benefit of a narrow edge
case in an already low-usage section of CSS. As such, I've decided not
to preserve the representation of these colors in compressed mode.

Closes #1001
Merge branch 'master' into bleeding-edge

Conflicts:
	VERSION
Revert "Make index() return a DeprecatedFalse object rather than null."

This reverts commit 6607785d256219083103d2cba5e10c581b30d3b5.
Add a changelog entry about index() returning null.
Merge branch 'null-index' into bleeding-edge
Merge branch 'master' into bleeding-edge

Conflicts:
	VERSION
Fix rubocop.
Merge branch 'master' into bleeding-edge
Rip out the deprecated addition of . to the load path.
Rip out support for passing lists of pairs to map functions.
Rip out deprecated argument names.

Closes #1118
Fix up the 3.3.0 changelog entry for index().