MFC r367900, r367902, r367903

r367900: syslog.conf(5): Fix a few mandoc warnings

• new sentence, new line
• skipping paragraph macro: Pp at the end of Sh

r367902: crashinfo(8): Fix a few mandoc warnings

• new sentence, new line

r367903: moused(8): Fix a few mandoc warnings

• new sentence, new line