preparations to simplify multiple api support

move api-related files into separate directory, namespace
random refactoring here and there
rename shared_state -> object_context
more refactoring
cosmetics; put back third API version
- add post-build scripts to bundle release, install locally, run tests in one click
- JC exports few c functions to run tests, produce Papyrus code
- add Papyrus compiler files
Merge branch 'feature/post-install-scripts' into develop
JString.wrap - ignore invalid input. fix a crash caused by non-ascii or non-utf8 encoded input string. Improve test
cosmetics

- update jansson to v2.6
lua error message refers to the first argument. close #34
'shup up' jc-state properly
v 3.1.1
v3.1.1

Conflicts:
	JContainers/src/object_context.hpp