Clean up benchmark tests.

Smaller is always better now (including in comparison ratio).
Numbers aligned in output.
Using std::chrono for timing.
Remove assertions from benchmarks.
Explicitly use default constructors for Sequence.

For copy-assignment, move-assignment, etc.
Comments on Sequence ctors.
Benchmarks for Sequence creation/slicing.
Changes to build on VS2013

Didn't like the default move-ctor.
Or boolean #define flags.
Debug info.
Document VS2013 bug around Sequence construction

shared_ptr should not be convertible to vector<shared_ptr>, but VS2013
makes it so and even prefers it to the conversion to shared_ptr<base>.
Fix most slicing tests on Windows

Casting to share_ptr<Base> to avoid the conversion to
vector<shared_ptr<Base>> that VS likes so well.
Fix infinite loop on Windows.

Copying from within own vector range was failing.
Update and annotate tests for Windows.

Note our favorite compiler bug workaround.
Change written code so it clearly shows the execution order; was having
different results on MSVC and Clang. Now it matches.
Switch back to Cinder Timer.

chrono::high_resolution_clock was odd on Windows.
Hoping this produces more consistent results.
Merge pull request #14 from sansumbrella/benchmarks

Windows bugfixes, benchmark cleanup.