Internationalization added.

git-svn-id: https://plugins.svn.wordpress.org/inline-google-spreadsheet-viewer/trunk@988716 b8457f37-d9ea-0310-8a92-e5e31aec5664
Add quicktag, on-line help, better try catch error position.

git-svn-id: https://plugins.svn.wordpress.org/inline-google-spreadsheet-viewer/trunk@988718 b8457f37-d9ea-0310-8a92-e5e31aec5664
Return a meaningful error on HTTP errors, too.

git-svn-id: https://plugins.svn.wordpress.org/inline-google-spreadsheet-viewer/trunk@988720 b8457f37-d9ea-0310-8a92-e5e31aec5664
Add translation file, documentation in readme, version bump to 0.5.1.

git-svn-id: https://plugins.svn.wordpress.org/inline-google-spreadsheet-viewer/trunk@988721 b8457f37-d9ea-0310-8a92-e5e31aec5664