fixed margins and fonts in headerbar. fixed bootstrap2 placeholder error

I adjusted the items in header-bar on pages using bootstap so it looks as smooth as in blueprint.

Also I fixed an error in bootstrap2 by introducing bootstrap-fix.css.scss which contains the styles for placeholders. These were written with a defective selector in bootstrap2, so they had no effect, causing the global search field to have dark text.

Fix for #4721.