Merge pull request #1 from jwenerd/master

Reintroduce admin formatting changes, Replace all variants of <br> tags in MathML
Merge pull request #2 from jwenerd/master

Prevent TinyMCE from striping MathML tags
bump version to 1.3.1; update release notes
add paulschreiber, jwenerd as contributors
remove trailing whitespace
code style fixes per PHPCS
Merge remote-tracking branch 'upstream/master'

Conflicts:
	readme.txt
Merge branch 'paulschreiber-master'