This tool checks the integrity of a range of commits, in particular references to the corresponding Jira issues.

Squashed commits:

ICU-20119 Adding first commit report.
ICU-20166 Handling tickets that do not require commits.
ICU-20166 Search Jira issues from extra commits
ICU-20119 Updating commit report.
ICU-20166 Adding copyright to commit checker tools.
ICU-20119 Updating commit report.
ICU-20166 Require ticket at beginning of commit message.
ICU-20119 Updating commit report.
ICU-20119 Updating commit report.
ICU-20119 Updating commit report.
ICU-20120 Updating commit report.
ICU-20166 Removing REPORT.md from source control.