Move scope border tweaking logic from VariableInspector to NodeScanner
Fix error at post condition loop node in VariableInspector

This fixes #374.
Merge pull request #375 from yujinakayama/fix-error-at-post-condition-loop

Fix error at post condition loop
Fix examples in the code documentation

YARD requires the code examples to be indented.
Some doc corrections

Improve how the documentation of these classes look in YARD.
Fix Travis CI

Fix the long line offence.
Update Changelog for #374
Allow braces around multi-line blocks if do-end would change the meaning.