submit_tag emits extra semicolon when no onclick options are provided

The submit_tag in form_tag_helper allows for an 'onclick' option to be bassed as one of the options hash items. Currently, if there is no 'onclick' item in the options hash then the submit_tag includes an extra semicolon in the generated onclick string.

This is caused by the .join(';') on the array of options when one of the options ('onclick') in this case, is nil.

This patch removes nil items from the options array before calling .join(';').

So, if you use this in your view:

submit_tag("Save", :disable_with => "Saving...")

Before the patch, the output looks like this:

After the patch, the output looks like this:

Notice the extra semicolon in the before patch output around this area:

this.disabled=true;this.value='Saving...;';*;*result =