Nicer Output

[trishume]

This PR does two things (if you like one but not the other I can revert one):

• Order postings in the generated transaction in the same order that they are entered. IMO this makes more sense because I can enter postings in the same order I enter them manually. For example I typically like to put expense categories before the asset used to pay for the expense.
• Omits unnecessary amounts, just like shown in the UI by using the same function to output to the file as is displayed in the UI.

@hpdeifel

[hpdeifel]

Perfect, thanks.

Please amend the commit and put some of the description of this pull request in the commit message. I like to have the information in the commit messages themselves.

I'll merge it afterwards. Thanks again.

[trishume]

Done.

[hpdeifel]

And merged. Thanks again!