RFR: 6945: Create build script for Windows

[Jean-Philippe Bempel]

Build script for windows mimics behavior of the *nix one

Special handling for Jetty server with killing it at the end of the action

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Commit messages:
 - 6945: Create build script for Windows

Changes: https://git.openjdk.java.net/jmc/pull/147/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jmc&pr=147&range=00
  Issue: https://bugs.openjdk.java.net/browse/JMC-6945
  Stats: 139 lines in 1 file changed: 139 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jmc/pull/147.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/147/head:pull/147

PR: https://git.openjdk.java.net/jmc/pull/147