Merge pull request #812 from lmorg/develop

doc: updated changelog

Merge pull request #785 from lmorg/develop

v6.0

Merge pull request #782 from lmorg/develop

#781 two parser bugs affecting `is-null`

Merge pull request #779 from lmorg/develop

updated date in changelog

Merge pull request #776 from lmorg/develop

v5.3.5000

Merge pull request #774 from lmorg/develop

v5.3.4000

Merge pull request #769 from lmorg/develop

v5.3

Merge pull request #757 from lmorg/develop

v5.2

Merge pull request #745 from lmorg/develop

v5.1

Merge pull request #737 from lmorg/develop

v5.0.9310