DOC: add 1.7.2 release notes

Conflicts:
	doc/source/release.rst
DOC: update 1.7.2 release notes

add two additional fixed bugs
MAINT: Fix release notes formatting.

Sphinx was complaining about the title/heading hierarchy. This
fixes those complaints.

(cherry picked from commit 686905399753267f4447daa5a0bff8ff49098fa0)

Conflicts:
	doc/release/1.8.0-notes.rst
DOC: fix layout of issue listings in release notes
Merge pull request #4005 from juliantaylor/release-notes-1.7

Add 1.7.2 release notes and fix some layout issues