add python2.5.patch
add python2.5_no_free_list.patch
fix python2.5 patch
remove python2.5 patch
fix compiler warning
document Python internal free lists
don't always import gc; use lazy import
make clean removes also dist/
Support collecting arbitrary user data using a callback

Snapshot.create(), DisplayTop() and TakeSnapshot() have has an optional
user_data_callback parameter/attribute
add color to DisplayUncollectable
add python2.5 patch