[ProQuest] Fix target regexp

Partially reverts change in 015fe586eeb3d2d44e7b354508bd6cba82ec487f
Previous version of the regexp was matching against proxied URLs, which was breaking automatic proxy detection. The fix in 015fe586eeb3d2d44e7b354508bd6cba82ec487f didn't account for additional elements in the path.
single book, search results

bookSection/ISBN

various

section titles and remove first edition

more fixes
[APA PsycNET] Fix double-spacing in place (and everywhere else)
Re https://forums.zotero.org/discussion/42355/apa-psycnet-double-spaces-in-place-variables/
Closes #812 (sorry @zuphilip)
Also, improve bookSection detection
[APA PsycNET] Update all tests to fix spacing and invalid fields
[Bib(La)TeX] Import subtitles
Re https://forums.zotero.org/discussion/42349/subtitles-in-biblatex-import/
Merge pull request #814 from aurimasv/bibtex-subtitles

[Bib(La)TeX] Import subtitles
add AEA Web translator
hopefully fix FT--hard paywall, so I can only do so much testing
Restrict Wikisource translator to en.wikisource.org
[Wikisource] Update tests
@adam3smith the multiple test doesn't seem to work even with defer. Not sure why, but I haven't looked very closely.
Merge pull request #808 from rm2342/master
adapted beck-online.js so that data is consistent with Juris-translator,...
[beck-online] Minor cleanup and detection tweaks.
Throw an informative message if multiple scraping fails due to restricted access, since there doesn't seem to be a way to tell ahead of time.
Tests not changed, just rearranged.
@zuphilip, @rm2342, please run through the tests again in Scaffold to make sure I didn't break anything.
Merge pull request #807 from proquest/safari-books
single book, search results
[Safari Books Online] Minor tweaks. Tests not changed.
CC @aepheus