Ensure rpyfn is defined when loading .rpyc files.
Better prediction of DynamicDisplayable.

If no predict function exists, the regular DD function is called,
and what it returns is now predicted.
Config changes:

* Increase the predict lookahead.
* Make RENPY_DEBUG_IMAGE_CACHE set the default value of config.debug_image_cache.
Increase the image cache size to 16 screens.

We should be able to afford this, and computers have more RAM than they used to.
Update the changelog.
Restore the current screen using try/catch.

This fixes a bug where the current screen could be set at an
inopportune time, causing crashes.

See: https://gist.github.com/vaendryl/97fb82b9cbee8bda0777
Pop dynamic when a lookup_return fails.
android: Log call errors to android.txt.
Merge pull request #474 from civalin/i10n/zh_TW

Add Traditional Chinese translation.
Update changelog.
Update: launcher/game/tl/spanish/common.rpy
Update: templates/spanish/game/tl/none/common.rpy
Merge pull request #475 from LuqueDaniel/update-es

Update es
Bump versio to 6.18.3.
Check Side for correct parameters and children.

Fixes #476.
Improve prediction of call/return.

We now model the return stack as part of the prediction process,
making it possible to perform prediction through a call and return
pair.

Fixes #288.
While at the main menu, predict the start label.

This should provide a better experience in the start-new-game case,
which is the first thing a player will see.

Fixes #478.
Update changelog with new prediction stuff.
Add _composite_parts for composite displayables.

For composite displayables (those with _main) set, this gives a list
of all components, other than the root widget, that make up the
displayable.
Transfer focus based on displayable replacement.

When a displayable in a screen that has focus/grab is replaced,
we transfer the focus to its replacement. This fixes a problem where
we would transfer grab only, which could lead to a permagrab condition.

Fixes #477.