add full_title application helper function
add header to application.html.erb and modify home.html.erb
add bootstrap and some custom css
move html5 shim for IE to layouts/_shim.html.erb
add partial for shim, header and footer
edit css for footer
edit custom.css.scss to use sass feature
change routes and remove default index.html
update link in header and footer, optimize static_pages_spec
add signup page