v1.3.0 - configurable indicators

The big, breaking-ish, change is configurable indicators.

v1.2.0

The primary user-facing changes involve polishing performance and user interface, and further enhancing customization options:

• integrate citeproc with citar cache
• add citar template modifiers, change citar-display-transform-functions so it defines these
• make citar-open-entry configurable; add an option to open in Zotero