RFR: 8260862 JFR: New configure command for the jfr tool

[Erik Gahlin]

Hi,

Could I have a review of a new configure command for the jfr tool. Purpose is to simplify changing event settings:

$ jfr configure method-profiling=high gc=detailed
Configuration written successfully to:


For more details, see CSR:
https://bugs.openjdk.java.net/browse/JDK-8260863

Testing: 
- jdk/jdk/jfr
- JMC recording wizard

Thanks
Erik

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Commit messages:
 - Remove tabs
 - Remove carriage return
 - Improve formatting
 - Remove mistakenly added file
 - Fix typo
 - Initial

Changes: https://git.openjdk.java.net/jdk/pull/3100/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3100&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8260862
  Stats: 3232 lines in 43 files changed: 2961 ins; 54 del; 217 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3100.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3100/head:pull/3100

PR: https://git.openjdk.java.net/jdk/pull/3100