This material adds the option to generate an alphabetical index from index markers in a docx file.
Merge branch 'master' of https://github.com/kovidgoyal/calibre
Updating source to 1.29
Style improvements and debugging in the docx indexing code
Merge branch 'master' of https://github.com/pgarst/calibre into index
Stylistic cleanups
Initial stab at parsing XE fields robustly
When parsing fields ignore unknown flags
DRY
Parse INDEX fields
Get rid of the option to control index generation

Index will be generated automatically, wherever the INDEX field exists
in the input docx file.
Temporarily disable index generation pending refactoring
Merge branch 'index'