Add profiling script

To aid debugging, design and make the world a better place, a little profiler
has been dropped in which returns stats for each path that has been requested.
Thanks to Miguel Grinberg for inspiration!
http://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-xvi-debugging-testing-and-profiling
Switch to Bootstrap Material-Design

Include the CSS and glyphs for the Bootstrap
material-design theme. Load the styles in the global layout-template.
Add navbar to global layout-template

Include the navigation menu on a global level in a dedicated block, so it can
be overriden when needed (e.g. to add the correct 'active'-classes on
navigation-elements). This navbar also contains the search-from, which has been
dropped from the index-template.
Externalize helper-functions

Consolidate small helpers in a dedicated module for inclusion wherever needed.
Currently, two helpers exist for date-parsing and human-readable bandwidth
values.
Create Graph-class

This module should contain a base class for every kind of graph (e.g. history
graphs), and specializations for the concrete instance (e.g.
bandwidth-history). These classes will mainly handle data-sanitation and
graphing functionality via matplotlib.
Add routes for graphs

Each graph is available via a dedicated URL. Include the routes for bridge and
relay graphs and polish some surrounding logic.
Dummy route for topten

As this URL is already called within the template, we need a dummy URL to
prevent breakage. Stub should be extended later.
Set up debug-toolbar

Integrate the Flask debug-toolbar. Change the app's config to enable the global
debug-option and set up a 256 Bit secure-key for sessions.
Output graphs for bridges and relays

Modify templates to deliver the correct graphs per bridge/relay.
This also contains a little fix which adds a 'name' attribute to the search
field, required for the correct GET-param.
Update readme
Add requirements.txt

Provide the necessary dependencies for the app. This can be used as input for
`pip install` and will also be read by e.g. heroku.