Fix lots of bugs to pass tests. split block grammars into self modules

Release v0.6.3 (#1508)

Release v0.6.3

Merge pull request #1441 from styfle/release-0.6.2

Release 0.6.2

Merge pull request #1421 from UziTech/release-0.6.1

Release 0.6.1

Merge pull request #1404 from styfle/release-0.6.0

Release 0.6.0

Merge pull request #1365 from styfle/release-0-5-2

Release v0.5.2

Merge pull request #1341 from markedjs/release-0.6.0

Release 0.5.1

Merge pull request #1322 from markedjs/release-0.5.0

Release 0.5.0

Merge pull request #1273 from 8fold/release-0.4.0

Release 0.4.0

Merge pull request #1157 from markedjs/release-0.3.19

Release 0.3.19