setup welcome page
Update layout/application file
 Install bootstrap v3.2
Add footer and header(support bootstrapv3)
Add language dropdown menu
Add locale files
modify html files to suppot locale
 Using cookies to remember locale
add sqlite3 for development and test
Merge remote-tracking branch 'upstream/master'

Conflicts:
	Gemfile
Use official bootstrap-sass gem instead of raw bootstrap stylesheets files.
delete inline stylesheet in application.html.erb
 make veryclean static_pages.css.scss
did some refinement to css files
Using sub path to do localization
re-implement dropdown menu to change locale
install slim gem
Using html.slim
refine slim & css file
Merge remote-tracking branch 'upstream/master'

Conflicts:
	Gemfile.lock
	app/assets/stylesheets/application.css.scss