Freeze all the things
Revert some freezes on non-literals
Use start and end of string rather than line matching in regexes.
Use stackprof for profiling.
Merge pull request #317 from Shopify/string-anchors

Use start and end of string rather than line matching in regexes.
Merge pull request #318 from Shopify/stackprof

Use stackprof for profiling.
Move definition for TableRow to the tags folder.
Merge pull request #320 from Shopify/move-table-row-tag

Move definition for TableRow to the tags folder.
Use render! in benchmarks to avoid making it faster by breaking things.
Merge pull request #322 from Shopify/use-render-bang-in-benchmarks

Use render! in benchmarks to avoid making it faster by breaking things.
move change to top
Use render! in tests to make debugging test failures easier.
Refactor to create tags with a parse class method instead of new.

By moving parse out of the initializer, we can call super at the start of
the initializers for subclasses, and avoid the nasty allocate hack.
Merge pull request #321 from Shopify/move-tag-parse-out-of-initialize

Refactor to create tags with a parse class method instead of new.
Allow newlines in tags and variables.
Merge pull request #323 from Shopify/render_bang_in_tests

Use render! in tests to make debugging test failures easier.
Merge pull request #324 from Shopify/multiline-tags-and-vars

Allow newlines in tags and variables.
Add missing PR reference and author to a History.md entry.
Allow quoted single curly braces in variables.
Make tag/variable termination error clearer.