Issue 17: Make paper size for the PDF export specifiable

[aportale]

http://code.google.com/p/phantomjs/issues/detail?id=17

Adding a new phantom property called "paperSize". It takes one of the two possible dictionary variants:
{ width: '200px', height: '300px', border: '0px' }
{ format: 'A4', orientation: 'portrait', border: '1cm' }

• If no paperSize is defined, the size is defined by the web page
• supported dimension units are: mm, cm, in, px. No unit means px.
• border is optional and defaults to 0.
• supported formats are: A3, A4, A5, Legal, Letter, Tabloid
• orientation (portrait|landscape) is optional and defaults to portrait

I'm considering implementing a short form like:
phantom.paperSize = 'A4';
...needs further investigation.

[ariya]

I think "If no paperSize is defined, the size is defined by the web page" is a behavior change to version 1.0? If yes, I'll add some note in the ChangeLog.

[aportale]

Yes, that's a change of default behaviour.
In 1.0, you got a driver-dependent (aka arbitrary) paper size: http://doc.trolltech.com/latest/qprinter.html#paperSize .
In 1.1, you get the same size (in pixels at 72 dpi) as you would get for png/jpg/gif renders.

I was hesitating changing the default. But the "driver-dependent" fact and inconsistency with the other graphics formats seemed a good argument for it. If requested, I'm willing to change the default back to 1.0 behavior, the change is trivial.

[aportale]

Ariya, something went wrong with the Pull request. I was hoping to get
https://github.com/aportale/phantomjs/commit/fbb524e62975dff46734c5cccb518f89f784c05b pulled.
But instead it became
3f9596a .

[aportale]

Ah, not true what I sais. I was just fooled by a merge commit.
Everything fine! :)