update the problem_report for pr-10
Merge branch 'dev'
update comment in vrbls_mc
Merge branch 'dev'
Merge branch 'master' of https://github.com/kunyuan/DiagMC-time
add update add_interaction
test for add_interaction
delete some test code
update problem_report for pr-11
midway to change draw
fix a bug in add_interaction
Merge branch 'master' into draw
Merge branch 'master' into dev

Conflicts:
	program/monte_carlo.f90
update drawing.
in the middle of remove_interaction
Merge branch 'master' into dev
add update remove_interaction
test1 for remove_interaction, fix some bugs