fix(logger): loosen up syslogparser's strictness

In jeromer/syslogparser, the format of the log message is *very* strict,
whereas rfc3164 is *very* loose. a message priority is not mandatory,
for example, and the timestamp format is loose.

The fix was to check if an angle bracket is the first character in the
log line. If it wasn't, then no priority existed and instead it's a
timestamp. I also had to add Deis's timestamp format as an accepted
format for parsing as well as some hoops around how the hostname/tag
is parsed. Hopefully this can get fixed with a looser log parser in the
future, but this works for now.

fixes the comments in #1757