Remove support for Fluent 0.4 syntax from python-fluent #106
Description
Fluent 0.5 was released in January 2018, let's remove the 0.4 syntax code-paths in the python Fluent parser.
Notably, that's old-style comments, tags?, sections and enforced =.
@stasm, happy to help here, unless you're like I waited to write this patch for a year, don't take it away from me.