Fix bad line breaking
Use native Object.keys
Refactor unit normalization
Expand unique() call
Trim units string passed to normalizeUnits()
Cache units normaization (nearly 2x speedup)
Check normalized units cache before trying to validate units

Performance improvement
Update package.json
Refactor simplify() and remove unique()
Fix wrong filename in .gitignore
Camelize base_unit_cache variable
No need to call #toBase when computing unit signature vector
JSLitmus can not be asynchronously loaded

document.write should not be used with asynchronous script
Reverting 62644d: No need to call #toBase when computing unit signature vector

No specs had been failing but it only works because we explicitely call toBase
elsewhere in the current code (it should be fixed)
Rename normalizeUnits() to parseUnits()
Stringify units
Update Readme
Cache stringified units int a nested map