Test ZendHttp adapter in CI environment

CURL and PECL_HTTP adapters set connection timeout and dns cache timeout.

CURL and PECL_HTTP adapters set connection timeout and dns cache timeout (which is equal to "timeout" option value)

Fixes: #267

Fixes: #267

Close <pre> tag in 1.1 example code

Excludes on stats

Add wildcard behavior for null endpoints in rangeQuery.

I believe the '*' range feature is a pretty common usecase of range
queries.  Right now, passing null to this function generates an invalid
SOLR phrase like 'field:[5 TO ]'.  Users can of course pass '*' to the
helper, but supporting null makes this common usecase easier to handle.

For example,

```php
$minValue = $request->get('min'); // returns null if min not specified
$maxValue = $request->get('max'); // returns null if max not specified
$range = $helper->rangeQuery('value', $minValue, $maxValue);
```

Adds support for hl.preserveMulti and per-field options.

- In the 1.1-check-solarium-and-ping.php example code, the <pre> tag is
  never closed after the var_dump. This fix closes the tag.

Fixed examples for registerQueryType arguments.

update composer with alias and update travis to include 5.5

Fix suggester parser with duplicates

When asking for a suggestion of something like "blac blac", solr will return the blac suggestion 2 times.

Fix pivot facet response parsing