Simple enhancement for easy overloading
minor #1284 Simple enhancement for easy overloading (arnapou)

This PR was squashed before being merged into the 1.15-dev branch (closes #1284).

Discussion
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Simple enhancement for easy overloading

More consistent algorithm which allow people to easily overload normalize method to their needs.

Commits
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87d4f08 Simple enhancement for easy overloading
fixed Filesystem::exists() to normalize the template name before checking the cache