[jgit-dev] commit hash as a hex string

[CG <cg@xxxxxxxxx>]

### Problem: Given 

	RevCommit commitId = ...

>From this I want to get the commit id in a string in hex format.

### Attempt 1

	commitId.toString

gives the hex + additional information, such as commit-time that I don't
want in the string.

### Attempt 2

	commitId.asObjectId.toString

same result as attempt 1

Of course, I can solve this in an ugly way by doing some regex matching,
but probably there is a more elegant way.

Any idea?

TIA