Merge branch 'release/1.0'
Merge branch 'develop'
Merge branch 'release/1.0.1'
Merge branch 'release/1.0.2'
Added some additional ideas to the readme.
WIP commit.
Full unit test coverage and needed code fixes.
Removal of unneeded imports.
Added needed import to test module.
Removed duplicate module.
Full test coverage for compound validators. Minor corrections.
Added geographic compound validators and tests.
Added callback attribute to reduce code duplication.
Made use of CallbackAttributes and added simple casters.

Might move the casters to the transformation sub-package later.
Added test covering trivial edge case.
Network patterns (IP, MAC, hostname, URI) with tests.
Cleaned up pattern validators (which need tests) and added network tests while fixing issues.
Add singleton instances.
Implemented date-related validators.
WIP, now with even more tests.