Tell a user when uploading module on plugin screen

Fixes #152
Let the module list table instance to be retrieved

Fixes #234
Use correct quotes

Fixes actions for bulk module actions not being fired correctly.
Because single quote were being used, the variable wasn’t being
interpolated into the action name.

See #234
Merge branch 'issue-234'
Update l10n validator ignores

See #152
Merge branch 'issue-152'