Shadowd

- Updated to Python 3

This update enables PIE and updates tests for newer Boost versions.

This update fixes a critical bug that is caused by null-bytes.

- Added integrity check
- Replaced blacklist filters with completely new filters
- Added cache for database access
- Added security limitations for requests and parameters
- Updated signature code to use timing independent comparison
- Removed unnecessary indices from database
- Replaced wildcards with stored procedures
- Added wildcard support to profile server ip
- Changed model structure
- Added resource to request
- Replaced learning with more general mode
- Added unit tests
- Added Travis-CI integration
- Added const-correctness

This update improves old and adds new Python connectors:
- Added werkzeug support
- Added Flask support
- Improved threat removal in Django connector

The last performance improvement introduced a small bug in the storage queue. If many requests are pushed to the storage queue at the same time it is possible that a small percentage of them are not saved permanently. This is not a critical bug, but it still should not happen.
- Fixed bug in storage queue
- Improved flooding database queries to allow to disable check