Visibility fixer
bug #358 Visibility fixer (keradus)

This PR was squashed before being merged into the 0.5.x-dev branch (closes #358).

Discussion
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Visibility fixer

Entirely rewrite fixer to use tokens instead of regexp, what fixes several problems in generated fixed code, eg functions _after_ class definition (mentioned in #332). Extends utests as well.

Commits
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a8ed71b Visibility fixer