Add more regression tests for tinycss2 bugs.
Identifiers may now begin with "--".

See bullet point two of: http://dev.w3.org/csswg/css-syntax/#changes-CR-20140220
The semicolon token should not be respected.

See: http://dev.w3.org/csswg/css-syntax/#consume-a-declaration0
After consuming the colon token, it states the declaration's value is the consumption of every subsequent component value, until we reach an EOF token.
Merge pull request #3 from ezequiel/ident

Identifiers may now begin with "--".
Merge pull request #4 from ezequiel/semicolon

The semicolon token should not be respected.
Add some test cases for tinycss2 code coverage.
Merge commit '9a5f5a0587c10637e156540e60c482a6fbea2484'
Spec change: -- can start an identifier.
`!` not followed by `important` is just another declaration value.
Merge commit '5afe94a8adbd6716eedb6b374d70995060f0664a'
`!` not followed by `important` is just another declaration value.
Do not serialize `;` for a single declaration.
Have the tokenizer optionally preserve source whitespace.
Include docs and test files in the distribution tarballs.
Test on PyPy3
100% test coverage!