Fixed double-encoding of attributes, and encoded element contents.

[joelstein]

Example code:

$gather = new Gather;
$gather->gatherUrl = 'https://example.com/bandwidth-call?test1=test1&test2=test2';
$bxml->addVerb($gather);

Expected XML output:

<Gather gatherUrl="https://example.com/bandwidth-call?test1=test1&amp;test2=test2"/>

Actual output:

<Gather gatherUrl="https://example.com/bandwidth-call?test1=test1&amp;amp;test2=test2"/>

Note that the ampersand (&) is double-encoded in the gatherUrl attribute.

This was introduced in #43. It appears the intent was to encode a DOM element's contents. But it also encodes all attributes.

There is no need to encode the attributes. See this example; attributes are encoded automatically.

See this comment about using htmlentities with DOMDocument::createElement. If what is needed is to encode the element's contents (for example, the SpeakSentence contents), then we should either encode the inner element contents, or use DOMDocument::createTextNode.

See this example; using createTextNode automatically an element's contents.

This pull request removes the code added in #43 and replaces it with code to use createTextNode() to encode the inner contents of verbs which need it.

[ckoegel]

This will be merged in in #45

[joelstein]

Thanks!