Fixes #11

Adding option panel;
Adding mirror site support;
Adding Chinese localization;

add custom user_agent to reduce the change of encountering recaptcha;
fix generated urls with editors' name;

• Add auto updating;
• Improve the query url with multiple authors (Thanks for Ghiclgi's suggestion);
• Add preference for base query url (beta);
  • Using an official site may cause failed query.

• Simplify the updating process;
• Shrinkage the count string length of ZSCC ("ZSCC: 0000001" => "ZSCC:00001");
• Remove state indicator of staleness;

Adaptation to Zotero v6.0.

New feature:

• When updating many items, a random time delay is added, which may avoid Google Scholar traffic detection and reduce the frequency of reCAPTCHA.

Summary:

• Improve the process of dealing with reCAPTCHA, especially in China;
• Fix url error when encounter special characters in the paper title;
• Add time delay mechanism to avoid reCAPTCHA;

Old releases can be found here: https://github.com/nico-zck/zotero-scholar-citations-forked