Set the System Identifier as a unique string.
Modifying var to output a 32-character hexadecimal number.
Merge pull request #1665 from shefik/unique_identifier

This PR was merged into zikula:1.4 branch.

Discussion
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Set the System Identifier as a unique string.

Use Case: At installation, it is useful to set a unique identifier (as a system var) that can be used to identify the system. This system var can be then to be used as string mapped to third-party services.

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| Refs tickets  | -
| License       | MIT
| Doc PR        | -

Commits
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aedf2da8ca7487fb714ce725743aa4694eb283c4 Set the System Identifier as a unique string. shefik
5d7ce0a5c6861eee447b3347baaf0796f6d4c04f Modifying var to output a 32-character hexadecimal number. shefik