RFR: 8277459: Add jwebserver tool [v2]

[Julia Boes]

> This change introduces jwebserver, a dedicated JDK tool for the Simple Web Server. 
> 
> A description is provided in a follow-up comment.

Julia Boes has updated the pull request incrementally with one additional commit since the last revision:

  address PR comments:
  * update module and package summary
  * add -version / --version option to usage
  * fix markdown formatting

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/6497/files
  - new: https://git.openjdk.java.net/jdk/pull/6497/files/80b55848..513c5a1a

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6497&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6497&range=00-01

  Stats: 164 lines in 11 files changed: 5 ins; 94 del; 65 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6497.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6497/head:pull/6497

PR: https://git.openjdk.java.net/jdk/pull/6497