Fix issue 57, and fix file open without close

The TextAdept module should now work with TextAdept 7.0. A bug was also
fixed regarding the TextAdept plugin where a temporary file wasn't being
closed. On Windows, this resulted in an inability to delete the file
thus my C:\ directory was being spammed with undeleted temporary files.
Merge pull request #69 from Kelet/master

Fix issue 57, and fix file open without close