add some stapsdt reference link into TODO file
unify EVENTDEF "kprobes:" and "uprobes:" into "probe:"

make it more simple to use, there don't have good reason
to separate kprobe and uprobe, and normally user don't care
on it, so use a simple string "probe" instead.

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>