* misra.py: Fixup load rules parser.
* misra.py: Report when rule text is missing in rule-texts file
* misra.py: Allow to skip misra checks not specified in rule-texts.
* misra.py: Remove top-level control flow.
Create separate class that stores settings, instead of global variables.
This is required to perform imports from misra.py for testing purposes.
* misra.py: Add simple pytest test for load rules.
* misra.py: Add document structure tests.
* misra.py: Exit after show rules table.
* misra.py: Add document structure tests.
* misra.py: Fixup import pitfall with python2
* misra.py: Minor fixes
Georgy Komarov