Check in tkaskdir.
Merge branch 'master' into android
Use rwobject.c that's included in pygame, rather than building
our own.
Remove obsolete renpy_font module.
Spend less time with the image cache locked.

The image cache is no longer locked for expensive operations,
such as image loads. While this may cause us to load an image
twice (in rare circumstances), it also lets us preload images
without blocking loads frome the main thread.
Use nogil_copy to copy surfaces.

Previously, we used the angle copy function to copy surfaces, which
used the pygame blit function. The pygame blit function was more
complex and held the GIL while blitting, and led to slowdowns in
loading.

Nogil_copy appears to be safe for Ren'Py, which doesn't use software
surfaces.
Remove extraneous debug print.
Remove duplicated docs.

Fixes #90.
Fix documentation issues.

Fixes #89.
Do not set the window size while entering/leaving fullscreen mode.
Add the ability to include empty directories to the zip format.

Per http://lemmasoft.renai.us/forums/viewtopic.php?f=32&t=2023
Add build.exclude_empty_directories variable.
Make loads after rollback non-greedy.

A greedy load after rollback can roll-back through with statements,
which are turned into with None statements until the start of the
next interaction. (Which is sensible behavior for the rollback
case, but fails when an after_load transition is scheduled.)

Fixes #95.
Fix race condition in the updater.

If the update finished while we were checking progress, zsync
wouldn't rename the file and the update would fail.
Bump version to 6.15.4.
Update changelog, document problems.
Make exclude_empty_directories deal with non-terminal directories.
Clarify what the Ren'Py license applies to.
Document config.start_callbacks.
Merge branch 'master' into android