Update release notes for M4
Update milestone number for 1.7 M4
Remove shortdesc replacement in PDF #1393

When shortdesc is defined in topicref, in PDF the map shortdesc is
pushed to the topic and replaces the topic shortdesc. This goes against
the DITA spec which only allows the map shortdesc to be used in
navigation.
Update release notes
Adding .gitattributes to make EOL constant

Following the convention described at
<https://help.github.com/articles/dealing-with-line-endings>.
Document plugin configuration and implementation features
Change filter file parameter to URI

Use Ant to create URIs instead of trying to construct them from file
path in XSLT.
Pass export.xml URL to conref XSLT as parameter

Instead of constructing the export.xml URL in XSLT from base and temp
directories, generate the URL directly with Ant's makeurl and pass it as
a parameter.
Normalize line feeds
Add deprecation comments to code
Normalize line feeds

[ci skip]
Clean XSLT imports #1409
Separate profiling filter into a separate filter #1312
Update test suite
Update test suite
Remove print attribute processing from DitaWriter

Print attribute processing was moved to ProfilingFilter and it should
have been removed from DitaWriter at the same time.
Fix mapref resolution role cascade #1413

Mapref will no longer cascade the role to target content.
Update test suite to fix mapref role cascading
Add support for abbreviated-form in PDF #1193

Support for abbreviated-form in PDF does not match XHTML as XHTML has
old legacy features that are not general enough or behavior does not
follow DITA 1.2 spec.

Keyref preprocessing has been changed to resolve href attribute from
keys to term and keyword elements. This allows output specific code to
work on resolved links, instead of processing keyrefs again.
Use xref link building templates for keyref link generation