updated for version 7.4b.022
Problem:    Not waiting for a character when the tick count overflows.
Solution:   Subtract the unsigned numbers and cast to int. (Ken Takata)
Added tag v7-4b-022 for changeset d5d6b78cff09
release version 7.4
Added tag v7-4 for changeset 359743c1f59a
Auto version upgrade (7.4.1)