Developer scripts

[hiker]

#2471 added a script to update the (c) statements, and I have two additional scripts that should be added:

• [ ] pycov: tests coverage for a file when given either a source filename, or a test file (assuming same directory structure and test filenames adding _test
• [ ] pycheck: besides pylint and pycodestyle, it checks if your name is in the file (ie. as author or modified by), if it contains a _future statement, and a mismatch of ` (which nearly always indicates a typo in a type).
• [ ] Document all three scripts in the developer guide