Added base Web App functionalities and models. Minor fixes.

docker-compose.yml

images/webapp/Dockerfile

images/webapp/code/rosetta/base_app/exceptions.py

...rosetta/base_app/management/commands/base_app_populate.py

images/webapp/code/rosetta/base_app/models.py

...bapp/code/rosetta/base_app/static/css/bootstrap-3.3.5.css

.../code/rosetta/base_app/static/css/bootstrap-3.3.5.min.css

.../base_app/static/css/bootstrap-datetimepicker-4.17.47.css

...e_app/static/css/bootstrap-datetimepicker-4.17.47.min.css

...tatic/css/bootstrap-datetimepicker-4.17.47.standalone.css

...pp/code/rosetta/base_app/static/css/stylish-portfolio.css

...osetta/base_app/static/favicon/android-chrome-192x192.png

...osetta/base_app/static/favicon/android-chrome-256x256.png

...code/rosetta/base_app/static/favicon/apple-touch-icon.png

...pp/code/rosetta/base_app/static/favicon/browserconfig.xml

...pp/code/rosetta/base_app/static/favicon/favicon-16x16.png

...pp/code/rosetta/base_app/static/favicon/favicon-32x32.png

...s/webapp/code/rosetta/base_app/static/favicon/favicon.ico

...p/code/rosetta/base_app/static/favicon/mstile-150x150.png

...ode/rosetta/base_app/static/favicon/safari-pinned-tab.svg