Close <pre> tag in 1.1 example code

- 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.
Adds support for hl.preserveMulti and option. This fixes #263.
Merge pull request #264 from michelole/preserveMulti

Adds support for hl.preserveMulti and per-field options.
Added exculde functionality to stats component
Added tests for stats field excludes
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);
```
Merge pull request #272 from nubs/master

Add wildcard behavior for null endpoints in rangeQuery.
Merge pull request #268 from juergen-vogel/master

Excludes on stats
Merge pull request #261 from davechez/fix-example-1.1-pre-tag

Close <pre> tag in 1.1 example code
Merge commit '1e5e9c380a970e22192a5a548d05db40e73d46a4' into develop
Support HTTPS Solr server

Fixes: #267
Merge commit 'b47b9cd21eaf75209da20cbc16d0740a130528f1' into develop
Support HTTPS Solr server

Fixes: #267
CURL and PECL_HTTP adapters set connection timeout and dns cache timeout (which is equal to "timeout" option value)
Merge pull request #281 from YevKov/connection_timeout

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