Merge pull request #60 from pikzen/master

Do not add a tag to the search if it's already being searched for.
 * Fixes https://github.com/shaarli/Shaarli/issues/50
 * Fixes https://github.com/sebsauvage/Shaarli/issues/140
Prevents ?do=addlink from generating a 404 if the user is not logged in
Fixes https://github.com/shaarli/Shaarli/issue/47
Merge pull request #61 from pikzen/shaarli47

Prevents ?do=addlink from generating a 404 if the user is not logged in
Fixes https://github.com/sebsauvage/Shaarli/issues/141
Fixes https://github.com/shaarli/Shaarli/issues/47
Added a link to the visible URL in the link list
Corrected CSS to prevent a line from showing underneath
Fixes https://github.com/shaarli/Shaarli/issues/53
Merge pull request #62 from pikzen/linkurl

Added a link to the visible URL in the link list
Feature: enable/disable permalinks for RSS
The option to see the shortlinks or permalinks has been added to the configuration panel. It is a simple checkbox
This option is disabled by default (meaning that shortlinks are the default)
Updated writeConfig() to save this option
Also fixed a slight typo in config.html.