RFR: 6946: There should be an option to build the agent in the build script [v3]

[Miroslav Wengner]

> https://bugs.openjdk.java.net/browse/JMC-6946
> added: 
> - build.sh --packageAgent
> - build.sh --runAgentExample

Miroslav Wengner has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains five additional commits since the last revision:

 - Merge branch 'master' of https://github.com/openjdk/jmc into feature/6946_There_should_be_an_option_to_build_the_agent_in_the_build_script
 - 6946: windows script update
 - 6946: typo correction
 - 6946: cleanup
 - 6946: build script -> build agent, run agent example

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

Changes:
  - all: https://git.openjdk.java.net/jmc/pull/183/files
  - new: https://git.openjdk.java.net/jmc/pull/183/files/6b4ac1a5..7e24b75a

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jmc&pr=183&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jmc&pr=183&range=01-02

  Stats: 74 lines in 11 files changed: 26 ins; 6 del; 42 mod
  Patch: https://git.openjdk.java.net/jmc/pull/183.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/183/head:pull/183

PR: https://git.openjdk.java.net/jmc/pull/183