Add new form for reschedule

+Add simulate rescheduling
Rescheduling when grace period>0

Delete old rescheduling form
Change reschedule loan event

add update script  13.8 to 13.9
Correct update script 13.9
Merge branch 'reschedule' of https://github.com/PavelBastov/opencbs into reschedule
Complete the switch to v13.9.
Clean up unit tests for rescheduling.
Fix unit tests.