First pass of getting rid of ComplexSelectorDeque and friends completely in favor of Node. The code runs, but 20ish tests fail. When debugging, I realized we weren't grouping the selectors the same way ruby sass was in extendCompoundSelector, so I implemented group_by_to_a to mimic the same behavior.
Fix for trim to properly skip comparing against the same sequence. Use toTrimIndex == resultIndex && seqs1 == seqs2 instead of toTrimIndex == resultIndex. toTrimIndex == resultIndex was introduced to fix a bug where ruby is doing object comparison instead of equivalency comparisions. What I didn't realize was that result gets written to during the iteration, and we do want to compare if the object has changed. So, try checking both. I'm not 100 percent sure this is the right fix, but it makes a lot of tests pass. Committing for now, and I'll noodle on it tomorrow.
Add a comment to the trim fix to explain the tricky logic.
Implement complexSelectorHasExtension for debug mode to check if a selector has an extension before running through the extend logic. This is mainly to get our printing to match up with ruby sass, which is why it is debug only. ruby sass only runs extend on selectors with extensions. However, libsass runs it on all selectors. The result of the extend code is the same selector if the selector doesn't have an extension, so this doesn't need to happen in release mode.
Fixed some more tests that were failing due to improper selector equality testing. We were getting duplicates because certain checks in ruby did not care about Simple_Selector ordering, but our call to Node::contains did. Implemented a selectors_equal method that takes a boolean that determines order dependence. Implemented the same things for our Node object and started calling it.
Merging in feature/extend-support to pick up the debugging printing changes. I changed the default print level in debug mode to be NONE instead of ALL. I also removed some commented out code. There should be no functional changes in this commit.

Merge remote-tracking branch 'origin/feature/extend-support' into feature/extend-support-node-only

Conflicts:
	extend.cpp
	sass_util.hpp