updating code, constructing options, trimming things down.

git-svn-id: https://plugins.svn.wordpress.org/double-opt-in-for-download/branches/working@822578 b8457f37-d9ea-0310-8a92-e5e31aec5664
Moved the landing page selection to the upload form to add the ability to have different landing page for different downloads.
Removed Admin Message about having download selected.
Updated language files.
Updated Admin Header with version number
Updated main file and install file with version numbers

git-svn-id: https://plugins.svn.wordpress.org/double-opt-in-for-download/branches/working@822837 b8457f37-d9ea-0310-8a92-e5e31aec5664