* update from ionicons-npm to ionicons ver.5
* drop the webfont built by grunt for icons
* built icons.html template for inlining icons with jinja2 into html
* update icon to use mostly the outline version
* add icons to categories and do not display them on mobile to save space
* remove all legacy ion icon font files from simple theme
* icons.html is added in this commit since make statc.build.restore requires git to know the file already
* cleanup error-dialog
"npm run webfont" to build the fonts directory.
It requires fontforge and ttfautohint distro packages.
partial revert of commit 7137d2893f33e9158e8563a21d9586119d175269
