GUI update: bower_components, angular-translate uses default loader and css moved to theme.css

First of all, sorry for this big pull request. #574 proposed to move the GUI files into subdirectories. Here is my proposal for using bower. Bower installs frontend packages like Bootstrap or Angular with one shell command, including dependencies. This makes it easier to use current versions of the packages and reduces work. Since the Bootstrap css included some modifications but bower installs standard Bootstrap I moved the few design changes to a new file called gui/theme.css. In this file I also moved the inline css and the raleway configuration. The last thing is that I changed the font format from TTF to woff because TTF is not well supported by Internet Explorer, and WOFF is the web standard.