add _removeHeader rename requestHeaders to _getRequestHeaders
Remove unnecessary private members only used in constructor
Rename remaining private members to underscore prefix and camelCase
Return boolean for execute, added public getCurlError
Change setClientHeader to take name and value as args
cleanup, follow camelCase for everything, more descriptive var names
Order members by private, protected, public, then alphabetical
Remove CURLOPT_USERAGENT, already set by header
phpdoc style class and member documentation
Refactor constructor, takes options array, but still excepts string as $proxyUri (see commit details)

The `$options` array consists of members:

 - **requestUri**
 - **requestMethod**
 - **baseUri**
 - **proxyUri**

**proxyUri** is required, while the rest are optional.

If **requestUri** is passed, it stands in place for both `$_SERVER['REQUEST_URI']` and `$_SERVER['QUERY_STRING']` which is used in translating the **proxyUri**.

Passing **requestMethod** is useful if you are making an API available but slightly different (either more or less secure).
Added options for "inputStream" and "data"
Added more examples
Merge pull request #9 from drkibitz/options-cleanup-refactor

Options cleanup refactor