- further fixes of inccorect overflow errors for int (and long on LLP64 systems) * prev commit had bugs * added overflow tests for also int, long, long long (for both, lp64 and llp64) - while at it, fixing a reference leak when not using python with utf8 caching

# manage by auto-reference?

# package foo uses dynport bar
#
# 1. dynport bar loaded - loads bar shared library
# 2. package foo uses bar
# 3. copy function from dynport
# 3. detach dynport bar
# 4.