Merge branch 'master' of https://github.com/cbhaley/calibre
Searching: When searching for identifiers, fix searching for values that contain colons not working
Make the Economist recipe respect bold text
Update Economist

Merge branch 'master' of https://github.com/felagund/calibre
Fix #1255671: escaped parenthesis do not work in any search expression, and match_books does not escape parenthesis.
Enhancement #1255676: match books should update the thumbnail as well as the metadata.