Renamed SWID measurement endpoint

- Moved `/api/sessions/<pk>/swid_measurement` to `/api/sessions/<pk>/swid-measurement`
- Moved endpoint from core app to swid app
- Added optional format specifier to "add tags" endpoint
Added coveralls
Handle entities with multiple roles
Improved & tested enforcement save view
Added SQL_DEBUG setting

With SQL_DEBUG enabled, all executed SQL queries get printed to stdout.
Optimized database access in swid-measurement endpoint
Moved inventory und log view js files to swid app
Added sorting to reported by device table
Changed result table-headers from td to th
Prevent dates and some titles from wrapping
Provided possibility to add file via gui
Moved swid log and inventory button to device report view
Inital set of hash-params does not influence browser history
Fixed some schema problems that occur with MySQL
Added initial data fixtures
Enabled non-interactive mode on setpassword command
Attached event to datepicker button
Added sorting to file paging
Added markdown as dependency

This is used to render API endpoint documentation.
Added --no-cov option to runtests.py