Added base Web App functionalities and models. Minor fixes.

.../rosetta/base_app/static/font-awesome/less/variables.less

...a/base_app/static/font-awesome/scss/_bordered-pulled.scss

...code/rosetta/base_app/static/font-awesome/scss/_core.scss

...setta/base_app/static/font-awesome/scss/_fixed-width.scss

...ode/rosetta/base_app/static/font-awesome/scss/_icons.scss

...de/rosetta/base_app/static/font-awesome/scss/_larger.scss

...code/rosetta/base_app/static/font-awesome/scss/_list.scss

...de/rosetta/base_app/static/font-awesome/scss/_mixins.scss

...code/rosetta/base_app/static/font-awesome/scss/_path.scss

...a/base_app/static/font-awesome/scss/_rotated-flipped.scss

.../rosetta/base_app/static/font-awesome/scss/_spinning.scss

...e/rosetta/base_app/static/font-awesome/scss/_stacked.scss

...rosetta/base_app/static/font-awesome/scss/_variables.scss

...setta/base_app/static/font-awesome/scss/font-awesome.scss

...bapp/code/rosetta/base_app/static/icons/mimetypes/apk.png

...osetta/base_app/static/icons/mimetypes/application-7z.png

...setta/base_app/static/icons/mimetypes/application-apk.png

...se_app/static/icons/mimetypes/application-archive-zip.png

...a/base_app/static/icons/mimetypes/application-archive.png

...etta/base_app/static/icons/mimetypes/application-gzip.png