Fix various typos.
+tck carry the original exception to fail(), helps tracking exceptions
=tck remove not used assertion method which could lead to NPE
Merge pull request #157 from ktoso/avoid-npe-ktoso

=tck remove not used assertion method which could lead to NPE
Merge pull request #148 from ktoso/impr-tck-stacktraces

+tck carry the original exception to fail(), helps tracking exceptions
Merge pull request #147 from 2m/various-typo-fixes

Fix various typos
Build improvements.

Updated to latest Gradle, aligned closer to previous SBT build and rationalised all configuration.