Strings not extracted for translation because of single quotation marks

There are some .js files which contain strings marked for translation, but the strings are not extracted into the pot file.

This is because gettext does not support JavaScript, and thus .js files listed in POTFILES.in will be considered as being the default syntax, which is C. However in C, only strings between double quotation marks are considered for extraction into the pot template, the ones between single quotation marks are not. The affected files are currently:

gabor@gabor-laptop:~/src/launchpad/webapps-applications$ grep -r \_\(\' *default-apps/Amazon/Amazon.user.js: addAction(_('Basket'), 'gp/cart/view.html');
default-apps/Amazon/Amazon.user.js: addAction(_('Wishlist'), 'gp/registry/wishlist/');
default-apps/Amazon/Amazon.user.js: addAction(_('Orders'), 'gp/css/history/orders/view.html');
default-apps/Amazon/Amazon.user.js: addAction(_('Manage your Kindle'), 'gp/digital/fiona/manage');
src/Twitter/Twitter.user.js: title = _('Tweets');
src/Amazon/Amazon.user.js: addAction(_('Basket'), 'gp/cart/view.html');
src/Amazon/Amazon.user.js: addAction(_('Wishlist'), 'gp/registry/wishlist/');
src/Amazon/Amazon.user.js: addAction(_('Orders'), 'gp/css/history/orders/view.html');
src/Amazon/Amazon.user.js: addAction(_('Manage your Kindle'), 'gp/digital/fiona/manage');