RFR: 1422: Remove the need to type `JEP-` or `jep-` prefix in `jep` command [v2]

[Guoxiong Li]

> Hi all,
> 
> This patch permits the strange grammer like `/jep jEP-123` and removes the need of the `JEP-` or `jep-` prefix.
> When the prefix (`JDK-`, `JEP-` or others) is not provided, the bot treats it as a JEP ID firstly.
> If the issue is not found, the bot then treats it as an issue ID.
> 
> Thanks for taking the time to review.
> 
> Best Regards,
> -- Guoxiong

Guoxiong Li has updated the pull request incrementally with one additional commit since the last revision:

  Fix some comments/messages. Adjust some test cases.

-------------

Changes:
  - all: https://git.openjdk.java.net/skara/pull/1311/files
  - new: https://git.openjdk.java.net/skara/pull/1311/files/5f9f5203..19bbf76c

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=skara&pr=1311&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=skara&pr=1311&range=00-01

  Stats: 28 lines in 2 files changed: 6 ins; 3 del; 19 mod
  Patch: https://git.openjdk.java.net/skara/pull/1311.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/1311/head:pull/1311

PR: https://git.openjdk.java.net/skara/pull/1311