Slow lexer and parser scaffold.
Replace hand-coded lexer with faster hacky lexer.
Descriptive comment for lexer
Bring back the lexer
Better lexer
Fancy StringScanner based lexer
Basic expression parsing
New variable parser!
Fix benchmarks to use only valid liquid.
Fix profiler
Unfinished if statement parser.
Test a different lexer architechture
Revert "Test a different lexer architechture"

This reverts commit 24ddaf1a9ce4d8c6ee5e8302d682c1f62e61954d.
Parsing for if statements
Allow ! in identifiers like Ruby
Add error mode switching
Add back tests for lax parsing
Add lexer tests and fixes
Add parser tests
Remove the Token class from the lexer in favour of less smart but faster arrays