Escape strings that contain an equal sign
Differentiate units with a : sign to ensure their parsability

literals also now exclude the : sign
Improved the parser a lot

 * Now supports units
 * Much more strict with whitespaces
 * Unescapes escaped quotes in a string
 * Handles the {...} notation that's used when reaching a maximum depth

There is still a unit test failing
More parsing, use sub-parsing in value literals
Merge branch 'parser-updates'