**Motivation**: We have decided to rewrite the documentation generator to add more features
to our documentation and to fix some outstanding bugs.
This PR addresses the following problem:
- Hard to add new features to the code base.
- The code was tied with Logstash.
- No easy way to publish the doc for a single plugin
- The plugin author was not able to test their documentation changes
- The reported errors were hard to understand.
- No easy way to automate it.
- the minimal requirement on base classes.
Fixes#5720
* move cli argument handling from agent to runner
* add a short-help message
* add interactive shell option
* log fatal messages to terminal when logging to file
* change docs:generate task to use bundle exec
Fixes#3872
remove unused load path
use either local core lib dir or logstash-core gem
include spec in logstash-core
do not include lib, spec and locales dirs in package root
environment bootstrapping in lib/bootstrap.rb
added comments
move pluginmanager out of logstash-core
kafla installation solved by pluginmanager refactor
refactor bootstrap code
refactor shell scripts to simplify and DRY, indirect rspec command to our ruby launcher
add bin/rspec
cut by half the bin/plugin and bin/rspec startup time
fix drip context
use printf instead of tr
updated Windows bin scripts
missing gemspec in gemspec
use gem instead of gemspec so our plugin manager can correctly install logstash-core
generate packages including locally built logstash-core gem
move jenkins developmnent dependencies into Gemfile, they do not belong in logstash-core
path leftover
clean help agent help usage message and remore rspec in available command
comments cosmetics
update Bundler dependency, all recent testing have been made with 1.9.4
updated .lock file with regard to updated Gemfile
cleanup gemspec, Gemfile and regen .lock file
added progress output
avoid dual require on version
closes#3096
