Allow translators to pre-select items in the "multiple" select item dialog.
Avoid potential exceptions
Fix translator tester
Make varDump more resilient to property access errors
Fix cross-domain wrapping under most circumstances.

Cross-domain wrapping was previously broken when a page loaded a page from a different SOP, which then loaded another page. Thanks to @aurimasv for debugging this. It's still broken if one page sets document.domain and another does not, since we should wrap in this case but we won't.

Fixes #202
Use the last version of the page for translation.
Pass url to detect function
Merge pull request #207 from aurimasv/SA-savePage

[Standalone] Pass url to detect function from savePages
[PDF metadata retrieval] Fix broken DOI scanning
Merge pull request #208 from aurimasv/PDF-doiScan

[PDF metadata retrieval] Fix broken DOI scanning
[WebPageDump] Don't crash when @import stylesheets are null (caused by adblock)
Fix debug output password hiding for HTTP.promise(), and add 'debug' option

'debug' option shows response text

The status code is also now displayed for 20x even without 'debug'.
Update Q library
Disable debug output on drag over tag
Fix WebDAV URL error message
Generalize Zotero.HTTP.promise() for other methods

Also make success codes configurable with an options parameter
File sync overhaul

- New promise-based architecture
- Library-specific file sync queues, allowing other libraries to
  continue if there's an error in one library
- Library-specific sync errors, with error icons next to each library
- Changed file uploading in on-demand download mode, which had been missing
- On-demand download progress indicator in middle pane
- More accurate progress indicator
- Various tweaks and bug fixes
- Various future tweaks and bug fixes
Fix getTotalFileSize() error for file sync downloads

Also fix 'undefined' in error panel for some errors
Call complete() when no translators are set. Don't fail when a translator returns without throwing an error or completing an item.
Make cleanISBN less aggressive. Should yield fewer false-positives.