Proposal for tightening the definition of the `SourceCitation.value` property and provisioning it with an explicit _italic_ styling mechanism.
Modifies the proposal for adding styling to the `SourceCitation.value` property.
Modifies the proposal for representing bibliographic metadata in the `SourceCitation.value` property.
Merge pull request #259 from FamilySearch/citation-italics

<i>italics</i> in citation text