fix files in console-and-shells folder

- completion-shell : theme => template
- i18n-shell : app => src
- upgrade-shell : for cakephp 2, so use old notations for app (no src)
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add fr community link in where-to-get-help
update upgrade shell
fix conflict
small correction in upgrade
fix small grammar
remove the fr community for now
add upgrade in keywords
change title in upgrade page
[fr] small grammar in contributing folder

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[fr] small grammar in controllers folder

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[fr] translations of behaviors folder

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Merge pull request #1701 from cakephp-fr/3.0-console-and-shells-small-fix

fix files in console-and-shells folder
[fr] update core-librairies folder

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