Added HOOK_FORMAT_ENCLOSURES plugin hook.

Runs HTML and enclosures array through a plugin hook when rendering an article's enclosures in format_article_enclosures(). Allows plugins to override handling of how enclosures are presented by either filtering the array of enclosures, or generating the HTML to add to the article content.
Changed how the enclosures array is checked for content so an empty array is not processed. Fixes a change from the previous branch commit.
Merge pull request #374 from dzaikos/plugin-hook-enclosures

Plugin hook enclosures
Add subscribe hook, give more information to fetch_feed hook
Merge pull request #375 from wltb/hooks

Add subscribe hook, give more information to fetch_feed hook
Update translation for fr_FR

New translations, fuzzy messages and typos corrections
Merge pull request #376 from morhelluin/master

Update translation for fr_FR
add hidden tunable _DISABLE_INACTIVE_FEEDS
new translations
include new lang codes
fix unicode problem from vim
Merge pull request #377 from bbraybrook/extra_langs

new translations
Revert "fix unicode problem from vim"

This reverts commit f33e373e59da004ade97643656f99f860cd34ef4.
Revert "include new lang codes"

This reverts commit e385861ca59abf0b1fc09d008339aaf4966ed0a6.
Revert "new translations"

This reverts commit 087e6e0ee101a4702cf2ece7f41bb7df47d3c2d4.
Revert "Revert "new translations""

This reverts commit e0215e1c0200d7899e381bea51f442e70e9e3645.
Revert "Revert "include new lang codes""

This reverts commit df13793f1cbd42c1298fc0be2d829c2dd290d5a5.
Revert "Revert "fix unicode problem from vim""

This reverts commit 0172de4244c30326dc4f03e08c7110f61c394d44.
include message headers
helps to know what month it is..