Feature/#56 section wise collation

Feature

Summary

This MR provides

• a new module, collate.xqm, which takes care of the collation process. Only passages following tei:milestone are considered for extracting text nodes.
• a new module, commons.xqm, which holds variables and functions used in several modules.
• a refactored version of the RESTAPI endpoint returning *.txt files.

Compliance to “Definition of Done”

• Unit tests passed
• Code reviewed
• Acceptance criteria met
• Functional tests passed
• Non-Functional requirements met
• Product Owner accepts the User Story

Use Cases

If you can, please provide use cases for this feature.

Documentation

• I updated the README (if applicable)
• I provided my functions with appropriate documentation
• I updated existing documentation

Tests

Are we able to test this new feature?

• Yes, everything can be done via unit tests.

Changelog

• I added a statement to the CHANGELOG.

Version number

• I bumped the version number in build.properties.

Related Tickets

Closes

#56 (closed)

/cc Mathias Göbel, Frank Schneider, Michelle Weidling