MODE-2241 Implemented the ability to specify the type of a property when importing initial content.

All standard JCR property types are supported, including references, weakreferences and binaries. Simple references (Modeshape specific) are also supported.
The format for explicitly defining the type of the property is:
```
<?xml version="1.0" encoding="UTF-8"?>
<jcr:root xmlns:jcr="http://www.jcp.org/jcr/1.0">
    <node1>
        <string_prop type="string">string</string_prop>
        <boolean_prop type="boolean">true</boolean_prop>
        <long_prop type="long">123456</long_prop>
        <decimal_prop type="decimal">12.3</decimal_prop>
        <date_prop type="date">1994-11-05T13:15:30Z</date_prop>
        <double_prop type="double">12.3</double_prop>
        <name_prop type="name">nt:undefined</name_prop>
        <path_prop type="path">/a/b/c</path_prop>
        <uri_prop type="uri">http://www.google.com</uri_prop>
        <binary_prop type="binary">io/file1.txt</binary_prop>
        <reference_prop type="reference">/node2</reference_prop>
        <weakreference_prop type="weakreference">/node2</weakreference_prop>
        <simplereference_prop type="simplereference">/node2</simplereference_prop>
    </node1>
    <node2 jcr:mixinTypes="mix:referenceable"/>
</jcr:root>
```