v1.7.0

This minor version release 1.7.0 of UniOffice contains the following fixes and enhancements:

Fixes and enhancements

• Support for merging docx documents [UO-19]
  Document now has an Append function to append another document to it
  Example for merging documents: https://github.com/unidoc/unioffice-examples/blob/master/document/merge-documents/main.go

• Improved document header creation and modification support [UO-63]
  Fixes #405
  New example for creating and updating header: https://github.com/unidoc/unioffice-examples/tree/master/document/doc-existing-header
  New example for creating header on even/odd pages: https://github.com/unidoc/unioffice-examples/tree/master/document/even-odd-header

• Improved schema support for union functions [UO-54]
  Fixes #243

• Fix to make document.RemoveParagraph remove from table cells also [UO-53]
  Fixes #412