Merge pull request #230 from XerTheSquirrel/update-versions-20190225

Update versions of dependencies.

Merge pull request #219 from XerTheSquirrel/correct-maven-sync-syntax…

…-error

Correct syntax error in call to maven sync.

Merge pull request #205 from XerTheSquirrel/issue-204-crashrcconf

Correct fatal crash related to missing configuration resource.

Merge pull request #202 from XerTheSquirrel/specified-version

Do not use a variable version number, make it constant.

[RELEASE 1.9.0] copy for tag v1.9.0

[RELEASE 1.8.0] copy for tag v1.8.0

[RELEASE 1.7.0] copy for tag v1.7.0

[RELEASE 1.6.0] copy for tag v1.6.0

[RELEASE 1.5.0] copy for tag v1.5.0

[maven-release-plugin] copy for tag v1.4.0