add support for charset param

if the response includes the charset param in the
content type header the body will have the
correct encoding set.

if the response has utf-16 set as the content
type it will try and do BOM detection. otherwise
it will default to big endian. this can be 
overridden with the assume_utf16_is_big_endian
option.

this makes the json parsing usable with utf-16 
since utf-16 will not parse correctly if it has
been incorrectly marked as ascii.
process charset parameter case insensitively
Remove trailing whitespaces
Adding java check in aliasing of multiple choices.

This is needed to hack around a lack of compatibility between
ruby 2.0 and jruby compat.version=2.0.
Merge pull request #204 from nixpulvis/jruby-fix

Adding java check in aliasing of multiple choices.
Merge pull request #201 from ikstrm/remove-trailing-whitespace

Remove trailing whitespaces
Merge branch 'content_type_charset_support' of https://github.com/benmmurphy/httparty into benmmurphy-content_type_charset_support
When an http response has two Set-Cookie in the header, response['Set-Cookie']
will return a single string. This string will be the two returned cookies
separated by a comma, concatenated together. Instead this should use
get_field('Set-Cookie') which returns an array of returned cookie strings.
The syntax of cookies is described in http://www.ietf.org/rfc/rfc2109.txt,
section 4.1. Cookies are attribute-value pairs, so split should only return 2
values. This will allow '=' within the value of a cookie.
Replace multi_json gem with stdlib JSON.

As of June 2013, multi_json will no longer be maintained.
Require ruby 1.9.3 or higher.
Latest json gem is a dependency.
Merge pull request #214 from caselas/replace_multi_json

Replace multi_json with stdlib json
Merge pull request #218 from dwnichols/master

Updating the handling of Set-Cookie in http responses
Do not pass proxy options to Net::HTTP connection if not specified

Ruby 2.0 has changed the Net::HTTP.new method so that if you don't specify
a proxy address it defaults to using the proxy specified by the http_proxy
environment variable (if set). Passing nil for the proxy address now means
that a proxy is never used even if the http_proxy environment variable is
set.

However HTTParty was always passing the proxy option values even if they
were nil, which meant that the defaulting to http_proxy environment variable
didn't work.

With this change the proxy values are only passed if http_proxyaddr is non-nil.
Improve documentation of ssl_ca_file, ssl_ca_path
Merge pull request #223 from jimparis/master

Improve documentation of ssl_ca_file, ssl_ca_path
Merge pull request #222 from ampedandwired/ruby2-proxy-0.11.0

Do not pass proxy options to Net::HTTP connection if not specified
Made SSL connections use the system certificate store by default.

- Set http.verify_mode to OpenSSL::SSL::VERIFY_PEER by default
- Use OpenSSL::X509::Store.new as certificate store unless another is specified

Adapted from Faraday.
See: https://github.com/lostisland/faraday/blob/b25adc0ca6b47eb5150494a735721579862990f0/lib/faraday/adapter/net_http.rb#L100
Fix a bug in which we attempt to decompress the body on HEAD requests, which have no body.