[crac] RFR: Environment vars propagation into restored process

[Roman Marchenko]

This PR provides functionality to propagate actual environment variables to a restored process, as well as the test for this functionality.

Env propagation is done in few steps:
- Store the actual environment before restoring
- After restoring, replace the restored `environ` with a new one.
- On `afterRestore` event, propagate the new environment into a restored process via `ProcessEnvironment`.

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Commit messages:
 - Merge branch 'crac' into env_propagation
 - Some minor changes
 - Used putenv once rather that setenv in a loop
 - Some style fixes
 - Propagating actual environment vars into the restored process.
 - Cleanup
 - Highlight global variables
 - Add new pacakge description
 - Update interface
 - Fallback to the restore complete time
 - ... and 5 more: https://git.openjdk.org/crac/compare/9ed96110...0270dc4b

Changes: https://git.openjdk.org/crac/pull/30/files
 Webrev: https://webrevs.openjdk.org/?repo=crac&pr=30&range=00
  Stats: 178 lines in 4 files changed: 174 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/crac/pull/30.diff
  Fetch: git fetch https://git.openjdk.org/crac pull/30/head:pull/30

PR: https://git.openjdk.org/crac/pull/30