rewrite to support formatting and nesting fields

[iulica]

The changes implement support for MERGE fields inside other fields, and formatting flags.

Description

Fields spanning several paragraphs are detected and proper integration with MERGEFIELDS values is implemented. Number and text formatting and flags are implemented. Support for date formatting is added, but not yet implemented. A framework for easier testing of formats is also added along with tests for all changes. Previous tests are also passed, although some tests are incorrect. For those tests a flag is implemented to be able to remove the workarounds for those tests after review. When documents with nested fields are created, these documents need to be updated, by selecting the whole document and pressing F9. There is a flag for auto-updating all fields when opening the document. Support for setting this flag is also added (no, always, auto). Default is no, for backward compatibility.

Motivation and Context

It allows using more complex documents, that have formatting and complex fields. Several issues are solved, mostly about using MERGEFIELDS inside other fields like IF or INCLUDEPICTURE.

102 #88 #80 #78 #60 #52 #40

How Has This Been Tested?

All the changes have their own tests.

Screenshots (if appropriate):

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.

[iulica]

The rewrite code is split into 4 different classes: MailMerge - main API, handles the reading/writing of the docx ZIP file, the parts of the document, and also getting the fields from the xml MergeDocument - handles multi-document mail merges (separators, etc) MergeField - one data field, handles the data formatting for one field MergeData - factory for MergeField handles the merge of replacement data into one part (body)