Lots of improvements to the plugin library

* Moved “add new plugin” into a modal wizard
* Adopt big friendly buttons
* Add plugin icons and readmes to “add new plugin” modal
* Use tabs for splitting plugins/themes/languages
* Consistent styling between the “add new plugin” modal and the
“installed plugins” control panel tab
* Behind the scenes, moved from addressing the library as
`recipes/defaults/tiddlers/<etc>` to `recipes/library/tiddlers<etc>`

core/ui/ControlPanel/Modals/AddPlugins.tid

@@ -0,0 +1,116 @@
+title: $:/core/ui/ControlPanel/Modals/AddPlugins
+subtitle: {{$:/core/images/download-button}} {{$:/language/ControlPanel/Plugins/Add/Caption}}
+
+\define lingo-base() $:/language/ControlPanel/Plugins/
+
+\define install-plugin-button()
+<$button>
+<$action-sendmessage $message="tm-load-plugin-from-library" url={{!!url}} title={{$(assetInfo)$!!original-title}}/>
+<$list filter="[<assetInfo>get[original-title]get[version]]" variable="installedVersion" emptyMessage="""install""">
+reinstall
+</$list>
+</$button>
+\end
+
+\define popup-state-macro()
+$:/state/add-plugin-info/$(connectionTiddler)$/$(assetInfo)$
+\end
+
+\define display-plugin-info(type)
+<$set name="popup-state" value=<<popup-state-macro>>>
+<div class="tc-plugin-info">
+<div class="tc-plugin-info-chunk tc-small-icon">
+<$reveal type="nomatch" state=<<popup-state>> text="yes">
+<$button class="tc-btn-invisible tc-btn-dropdown" set=<<popup-state>> setTo="yes">
+{{$:/core/images/right-arrow}}
+</$button>
+</$reveal>
+<$reveal type="match" state=<<popup-state>> text="yes">
+<$button class="tc-btn-invisible tc-btn-dropdown" set=<<popup-state>> setTo="no">
+{{$:/core/images/down-arrow}}
+</$button>
+</$reveal>
+</div>
+<div class="tc-plugin-info-chunk">
+<$list filter="[<assetInfo>has[icon]]" emptyMessage="""<$transclude tiddler="$:/core/images/plugin-generic-$type$"/>""">
+<img src={{$(assetInfo)$!!icon}}/>
+</$list>
+</div>
+<div class="tc-plugin-info-chunk">
+<h1><$view tiddler=<<assetInfo>> field="description"/></h1>
+<h2><$view tiddler=<<assetInfo>> field="original-title"/></h2>
+<div><em><$view tiddler=<<assetInfo>> field="version"/></em></div>
+</div>
+<div class="tc-plugin-info-chunk">
+<<install-plugin-button>>
+</div>
+</div>
+<$reveal type="match" text="yes" state=<<popup-state>>>
+<div class="tc-plugin-info-dropdown">
+<div class="tc-plugin-info-dropdown-message">
+<$list filter="[<assetInfo>get[original-title]get[version]]" variable="installedVersion" emptyMessage="""This plugin is not currently installed""">
+<em>
+This plugin is already installed at version <$text text=<<installedVersion>>/>
+</em>
+</$list>
+</div>
+<div class="tc-plugin-info-dropdown-body">
+<$transclude tiddler=<<assetInfo>> field="readme" mode="block"/>
+</div>
+</div>
+</$reveal>
+</$set>
+\end
+
+\define load-plugin-library-button()
+<$button class="tc-btn-big-green">
+<$action-sendmessage $message="tm-load-plugin-library" url={{!!url}} infoTitlePrefix="$:/temp/RemoteAssetInfo/"/>
+{{$:/core/images/chevron-right}} open plugin library
+</$button>
+\end
+
+\define display-server-assets(type)
+Search: <$edit-text tiddler="""$:/temp/RemoteAssetSearch/$(currentTiddler)$""" default="" type="search" tag="input" focus="true"/>
+<$reveal state="""$:/temp/RemoteAssetSearch/$(currentTiddler)$""" type="nomatch" text="">
+<$button class="tc-btn-invisible">
+<$action-setfield $tiddler="""$:/temp/RemoteAssetSearch/$(currentTiddler)$""" $field="text" $value=""/>
+{{$:/core/images/close-button}}
+</$button>
+</$reveal>
+<div class="tc-plugin-library-listing">
+<$list filter="[all[tiddlers+shadows]tag[$:/tags/RemoteAssetInfo]server-url{!!url}original-plugin-type[$type$]search{$:/temp/RemoteAssetSearch/$(currentTiddler)$}sort[description]]" variable="assetInfo">
+<<display-plugin-info "$type$">>
+</$list>
+</div>
+\end
+
+\define display-server-connection()
+<$list filter="[all[tiddlers+shadows]tag[$:/tags/ServerConnection]suffix{!!url}]" variable="connectionTiddler" emptyMessage=<<load-plugin-library-button>>>
+
+<<tabs "[[$:/core/ui/ControlPanel/Plugins/Add/Plugins]] [[$:/core/ui/ControlPanel/Plugins/Add/Themes]] [[$:/core/ui/ControlPanel/Plugins/Add/Languages]]" "$:/core/ui/ControlPanel/Plugins/Add/Plugins">>
+
+</$list>
+\end
+
+\define plugin-library-listing()
+<$list filter="[all[tiddlers+shadows]tag[$:/tags/PluginLibrary]]">
+<div class="tc-plugin-library">
+
+!! <$link><$transclude field="caption"><$view field="title"/></$transclude></$link>
+
+//<$view field="url"/>//
+
+<$transclude/>
+
+<<display-server-connection>>
+</div>
+</$list>
+\end
+
+<$importvariables filter="[[$:/core/ui/PageMacros]] [all[shadows+tiddlers]tag[$:/tags/Macro]!has[draft.of]]">
+
+<div>
+<<plugin-library-listing>>
+</div>
+
+</$importvariables>