BIGTOP-3175. [Build] Support to specify commit SHA1 when building packages

[evans-ye]

No description provided.

[youngwookim]

@evans-ye Good job! minor nits:

• The sha-1 hash for commit is 'Commit Hash' I think 'commit hash' is easier to understand.
• It would be nice if you add a content for the feature into README.md - https://github.com/apache/bigtop/blob/master/README.md#for-developers-building-a-component-from-git-repository

[evans-ye]

@youngwookim

• Change property name from git_sha1 to git_commit_hash.
• Change property name from comp_version to base_version.
• Add documentation:
  https://github.com/evans-ye/bigtop/tree/BIGTOP-3175#for-developers-building-a-component-from-git-repository