#103 Support for text fields

[Bart Hanssens]

ODF 1.1, section 6.2 defines several text fields that can be used like
- current date / time + possible adjust
- full file name
- info about the "sender" of the document

These are especially useful for project management documents, but apparently they aren't supported yet

(tested with MSO2003 + Add-in R5154)

[Bart Hanssens]

Test document containing several text fields