New cell pseudo-type text

[jferard]

Some cells may contain complex text, similar to the footer/header text. With new cell pseudo-type, it would be easy to do that.
String version:
TableCell.setStringValue("string")
Outputs a very short XML:

<table:table-cell office:value-type="string" office:string-value="string"/>

Text version (see syntax for builder here #14):
TableCell.setTextValue(TextValue.builder().<some methods to build the text value>.build())
Outputs a longer XML:

<table:table-cell office:value-type="string" calcext:value-type="string">
    <text:p>
        <text:span text:style-name="...">te</text:span><text:span text:style-name="...">xt</text:span>
    </text:p>
</table:table-cell>

[jferard]

See http://docs.oasis-open.org/office/v1.2/os/OpenDocument-v1.2-os-part1.html#__RefHeading__1415146_253892949 and http://docs.oasis-open.org/office/v1.2/os/OpenDocument-v1.2-os-part1.html#__RefHeading__1415196_253892949 for possible improvements.

[jferard]

There is in 0_1_2 branch a new class Text. It should work with a little glue...