Added alt attribute to img tag and text input for user
Oops, get the value from the alt_text input element
Increased the width of the dialog box by 30px. Now 350px wide.
Added Russian translation for 'Image description' and removed alt_text tag from other lang files
alt_text tag is needed in lang files. Added it back in and defaulted remaining languages to en until they are translated.
Added French translation for image description
Merge pull request #27 from nathanshox/alt-text

Add alt attribute to img tag and input for user to set it