Trim change description before hashing them.

[rdunklau]

The change description is part of the change id. It would be great to trim it before hashing it. For example, if someone leaves a trailing space at the end of the change description, and someone else later removes it, the (deployed) change cannot be found in the plan anymore, resulting in a hard-to-track error.

[theory]

The note should always be trimmed already, both in the constructor and in the prompt code, which is the only place the note attribute should be written to other than the constructor.

[rdunklau]

I just tested this against the git version, and I was able to reproduce it:

• add a change. When sqitch fires up your editor, add trailing spaces at the end of the note.
• deploy
• edit the sqitch.plan file by hand, and remove the trailing spaces
• deploy

Result: Cannot find 0b73975c9c5108da5fd125a725873b569bc7caa8 in the plan

[theory]

Hrm. For some reason, I made it so that only vertical whitespace was trimmed. No idea why I did that.