Added "data.tx.timeout", default value and description; corrected description of "data.tx.janitor.enable"; fixed formatting of "weave.jvm.gc.opts"
Changed all occurrences of "weave" to "twill" and "Weave" to "Twill".
Merge pull request #866 from caskdata/feature/r2.6.0_fix_config_docs

CDAP-1068 Correction to cdap-site.xml documentation