make it possible for user to overwrite defaults

it's always unwise to set pre-defined, fixed flags. configuration should
be done in logstash.conf. making application run "out-of-box" and rc.d
script complex is a major PITA.

- add logstash_java_flags to set jvm flags, such as -Xmx${n}m
Merge pull request #51 from reallyenglish/tomoyukis

make it possible for user to overwrite defaults
create logstash user

UID 701 was choosen because:

- new user will get 9xx assigned in the upstream and collides
- it's unlikely that lmp (701 in /etc/services) will be used
Merge pull request #52 from reallyenglish/tomoyukis

create logstash user
bugfix: s/logstash_flags/logstash_agent_flags/

because ${name}_flags is passed to ${command} (/usr/bin/daemon in this
case)
Merge pull request #53 from reallyenglish/tomoyukis

bugfix: s/logstash_flags/logstash_agent_flags/
bugfix: quoting is required if variable to test contains space
Merge pull request #54 from reallyenglish/tomoyukis

bugfix: quoting is required if variable to test contains space
bugfix: run as logstash
Merge pull request #55 from reallyenglish/tomoyukis

bugfix: run as logstash
bugfix: do not bump PORTVERSION
Merge pull request #56 from reallyenglish/tomoyukis

bugfix: do not bump PORTVERSION
bugfix: decrement PORTVERSION again
Merge pull request #57 from reallyenglish/tomoyukis

bugfix: decrement PORTVERSION again
bugfix: create and chown piddir

- cd to etc dir where configs are located, not /usr/local/logstash
Merge pull request #58 from reallyenglish/tomoyukis

bugfix: create and chown piddir
manually merge 1c3dd91 to update rsyslog7 to 7.2.7

by "git show 1c3dd91fdd6056cd62e0499b88f5e5f382f633c2  . | git apply
--reject -"

at least we need 7.2.5, which contains a critical bug fix.
http://bugzilla.adiscon.com/show_bug.cgi?id=411

1c3dd91 the commit
e2ed082 ignored because security/libgcrypt is not updated in branch
reallyenglish
a011d2c USES is not merged in our branch
1357769 USES is not merged in our branch
c18b1a2 harmless
Merge pull request #59 from reallyenglish/tomoyukis

manually merge 1c3dd91 to update rsyslog7 to 7.2.7