Compatibility with Piwigo 12

* compatibility with Download Permissions

New languages:
* Catalan (Català [CA])
* Czech (Česky [CZ])

* hide button if high definition is disabled bug
* hide button for embedded videos

$conf['custom_download_link_position'] can be set to 'properties-before' or 'properties-after'

Ability to move the download link before the list of photo properties with $conf['custom_download_link_position'] = 'properties'; in the local configuration

New languages:
* Japanese (日本語 [JP])
* Norwegian (Norsk bokmål [NO]), thanks to paulen
* Serbian (Српски [SR])
* Ukrainian (Українська [UA])

Checked compatibility with Piwigo 2.7

New languages:
* Bulgarian (Български [BG]), thanks to turnokopa
* Brezhoneg [FR], thanks to yves.kerleguer
* Danish (Dansk [DK]), thanks to Kaare
* German (Deutsch [DE]), thanks to quovadit
* Greek (Ελληνικά [GR]), thanks to bas_alba
* Esperanto (Esperanto [EO]), thanks to sylvbarrier
* Spanish (Español [ES]), thanks to jpr928
* Persian (فارسی [IR]), thanks to Garcia
* Finnish (Finnish [FI]), thanks to lrd
* Hungarian (Magyar [HU]), thanks to asicu.com
* Italian (Italiano [IT]), thanks to Ericnet
* Latvian (Latviešu [LV]), thanks to agrisans
* Dutch (Nederlands [NL]), thanks to Kees Hessels
* Polish (Polski [PL]), thanks to T00kie
* Portuguese Brazil (Brasil [BR]), thanks to flaviove
* Portuguese (Português [PT]), thanks to ANO
* Romanian (Română [RO]), thanks to norboo
* Russian (Русский [RU]), thanks to Konve
* Slovak (Slovensky [SK]), thanks to dodo
* Slovenian (Slovenščina [SL]), thanks to MarkoAm
* Swedish (Svenska [SE]), thanks to kabo
* Turkish (Türkçe [TR]), thanks to LazBoy
* Vietnamese (Việt [VN]), thanks to dummy
* Chinese (中文 (简体) [CN]), thanks to dennisyan
* Hong-Kong (中文 (香港) [HK]), thanks to hkdigit
* Traditional Chinese (中文 (繁體) [TW]), thanks to azq1231

First version