Remove onbeforeupload attributes instead of setting them to "".

This fixes extra "onbeforeupload" in saved files.
Fix removal of wa-color and wa-title elements.

getElementByTagName returns "live" NodeList; existing code was only removing every other element.
fix links enabling
Merge pull request #18 from kmike/onbeforeupload-cleanup

Remove onbeforeupload attributes instead of setting them to ""
Merge pull request #19 from kmike/element-removal-fix

Fix removal of wa-color and wa-title elements.
Merge pull request #20 from kmike/fix-links-enabling

fix links enabling
DTD menu items are disabled by default (at first install)
Checked that toolbar button is loaded before modifying it (+ corrected a file path)
useless comment removed
Removed useless variable contentPath and its uses
Removed unnecessary creation of CSS files for each schema.
Merge pull request #21 from xtannier/xtannier-DTDimport

Bug at first install
Release 1.17
Add an option for edit/delete popup delays. Use a shorter "show popup" delay (100) by default.
Merge pull request #22 from kmike/popup-delays

Add an option for edit/delete popup delays. Use a shorter "show popup" delay (100) by default.
Updated locale strings for popup delays
Merge pull request #1 from xtannier/master

latest from Xavier