Fixing slider issues with smarty math function

Adds option to display multiple random images

Bug fixed on redirection for admins.

#5 make it possible for admins to be subject to redirect

$conf['ExtendedDescription']['redirect_admins'] = true;

New icon to open help popup.

Compatibility with Piwigo 12

replace list of pages by tabs

* No more error message on log in page, coming from [login-link]. Requires Piwigo 2.9.2 (which is not available yet), by plg
* Make tag parameters case insensitive, add size aliases, by mistic

Compatible with Piwigo 2.7

new: [login-link] and [logged] tags
new: reworked the documentation

fixed: < !--more-->, < !--up-down-->, < !--complete--> tags not working correctly
fixed: strange behavior of [slider] with photos of different ratios

fixed: Deprecated: preg_replace(): The /e modifier is deprecated
fixed: [random] no working with no argument

New languages:
* Persian (فارسی [IR]), thanks to ipic
* Slovenian (Slovenščina [SL]), thanks to MarkoAm

Fix for buggy 2.5.b
--

Changes for [slider] :
- "control" can be setted to "thumb" to activate thumbnails navigation
- "thumbs_size" controls thumbnails size (in pixels)
- force no border on images

New languages:
* Bulgarian (Български [BG]), thanks to turnokopa
* Esperanto (Esperanto [EO]), thanks to sylvbarrier
* Estonian (Estonian [EE]), thanks to Eggy
* Lithuanian (Lietuvių [LT]), thanks to vilisas
* Norwegian (Nynorsk [NO]), thanks to kiho
* Romanian (Română [RO]), thanks to smarmie
* Traditional Chinese (中文 (繁體) [TW]), thanks to tedx

Compatible with Piwigo 2.5 (by mistic100)

Fix notice introduced with version 2.4.f

[random] tag can be used without 'album' parameter, randomizing on the whole gallery

[random album=10] will work even if the current user doesn't have access to album 10

Languages tags differentiate [lang=fr_FR] and [lang=fr_CA].
Syntax [lang=fr] still work.

Improve [slider] display

- the [redirect] tag now works in Additional Pages and photo description
- add the general trigger 'get_extended_desc' for other plugins
- new languages : Portugues (Brasil), Thai

- new tag [slider album=xx], see integrated help for full documentation
- all tags work on the gallery header
- [img] is deprecated, use [photo] instead

- Fixed fatal error with [random] or [photo] and Stripped theme
- Changed default [random], link=no

- Error fixed for images with description:
Fatal error: Call to undefined function assign() in
/..../piwigo/plugins/ExtendedDescription/main.inc.php on line 434

- Updated [img] and [random] for Piwigo 2.4 url format
- Added [photo id=xx album=yy size=SQ|TH|XXS|XS|S|M|L|XL|XXL html=yes|no link=yes|no]
- Added new languages. Thanks to all translators:
* Catalan (Català CA)
* Danish (Dansk DK)
* Dutch (Nederlands NL)
* Portuguese (Português PT)
* Russian (Русский RU)
* Ukranian (Українська UA)

Note: ([cat] still not works properly)

To translators: the file "help.html" has been updated http://tinyurl.com/6rts24u

Multilanguage tags are correctly displayed after a quick search (piwigo 2.3.1 is required).
Url for multilanguages tags is corrected.

Bug corrected for [cat] tags.

Compatible with the new multilanguage tags in Piwigo 2.3

bug fixed: img src correct on random photo, even if $conf['question_mark_in_urls'] = false

New pattern [random album=xx]
Turkish language added
Polish language added

tag is compatible with Piwigo 2.2.x.

[redirect ...] on "home / level1 / level2" was applied to "home / level1" as well

Fixed incompatibility with $conf['question_mark_in_urls'] = false.

Avoid error on redirection if $conf['category_url_style'] = 'id-name'.

New language no_NO - Norwegian thanks to atlew

New language ar_SA - Arabic / Saudi - العربية thanks to bakir

Add [redirect] tag: you can now easily create redirected categories. This tag can be used like that:
[redirect http://piwigo.org]
[redirect img=123]
[redirect cat=45]
[redirect search=67]

New language cs_CZ - Česky - Czech thanks to pab

New language hu_HU - Magyar - Hungarian thanks to sámli
New language lv_LV - Latviešu - Latvian thanks to Aivars Baldone

Add zh_CN - 简体中文 - Chinese. Thanks to winson

r7174

r7138

Add sk_SK - Slovak (Slovensky). Thanks to Dodo

update ES thanks to jpr928
udate IT/DE thanks to sugar888

For the [img] tags, adding the property 'titleName' which allows you to assign the name of the photo inside the