Update config system - Githubissues

Standardize merge rules (require merging to be explicit)
Break down some config functions (like loadConfig) into more targeted functions, making them more useful for external callers
More clearly separate config functions from executor
Clean up cross-environment config handling (node and browser)
Improve typings
Move some tasks that had been handled by config (showConfig, help) into the UI
Improve config unit tests

resolves #1109

theintern / intern