fix removing field with reference to array items & specs

Fixes #1990
Allow unary operators and comparable on timestamp object closes #2052

Fixes #2061
style preference

Fixes #2061
Fix for handling accessor sets on array elements.

Previously: Filters like mutate would throw an exception when attempting
to convert an element within an array to a specific type. This was
raising an error because the index in the field reference was being
treated as a String instead of an integer representing the index of the
field to convert.

Now: Plugins like Mutate can access and convert elements within arrays
to specific types, or, updating their values.

Fixes #2051
[JIRA-2046][JIRA-2181] fix usage help

Fixes #1354
Add code climate badge to show off :)

Fixes #2114
Use logstash-devutils

Fixes #2117
Update Gemfile for package testing

Fixes #2119
added apache logs, changed description and now computes top 20%

Fixes #2120
add test to sprintf to cover metadata support

Fixes #2149
install default plugins via bundler

Fixes #2107
handle vendored/nonvendored ruby and reset env vars

Fixes #2107
fix gem_home setting in environment.rb

Fixes #2107
codec#on_event api change

Fixes #2140
Avoid static file corruption (small.png) on Windows

When using `logstash web` on Windows the Kibana Logo on the dashboard is broken. This is because it will return small.png with 479 instead of 480 bytes (removing a 0x0d).

Fixes #1796
fix doc inconsistency about the versions in the getting started guide

Fixes #2109
clean up some reference to logstash.net in benefit of the es site

Fixes #2109
fix the release notes ascii docs style

Fixes #2109
add a reference to the plugins page within the logstash getting started tutorial

Fixes #2109
Add /var/log/logstash as an empty directory.

Testing deb package

    % dpkg -c build/logstash_2.0.0.dev-1_all.deb | grep var/log/logstash
    drwxrwxr-x 0/0               0 2014-12-01 22:29 ./var/log/logstash/

Testing rpm package

    % rpm -qvlp build/logstash-2.0.0.dev-1.noarch.rpm| grep var/log/logstash
    drwxrwxr-x    2 root    root                        0 Dec  1 22:34 /var/log/logstash

Fixes #2146

Fixes #2159