Add the pixel_width property to input.

This allows one to limit the width of an input field to a certain
number of pixels.

Fixes #254.
Fix documentation.

Thanks to Koichi Akabe for the proofreading.
fix typos
Merge pull request #261 from vbkaisetsu/fix-doc

fix typos
QuickSave shouldn't take a screenshot while in a menu.

Fixes #251.
Do not include binary files in the source distro.

Fixes #256.
Change the tutorial music to Sunflower Slow Drag.

This was the music used (as a midi file) for the very oldest versions
of the Ren'Py.

We use a 1994 recording by the US Marine Band, taken from
Wikipedia. It's public domain due to age (of the original) and due to
being the work of the US Government (for the recording).
Add Preferences("display", "any window").

This is selected when in any windowed mode, and changes back to the previous
window size.