standardize plugins, update metadata

add about-plugin metadata
chmod -x plugins
cleanup filenames to standardize on x.plugin.bash format
only plugin files intended to be executable from the command line should
contain a shebang line, and should be a+x.

plugins/available/javascript.plugin.bash

@@ -0,0 +1,41 @@
+# The install directory is hard-coded. TODO: allow the directory to be specified on the command line.
+
+cite about-plugin
+about-plugin download jquery files into current project
+
+[[ -z "$JQUERY_VERSION_NUMBER" ]] && JQUERY_VERSION_NUMBER="1.6.1"
+[[ -z "$JQUERY_UI_VERSION_NUMBER" ]] && JQUERY_UI_VERSION_NUMBER="1.8.13"
+
+function rails_jquery {
+  about 'download rails.js into public/javascripts'
+  group javascript
+
+  curl -o public/javascripts/rails.js http://github.com/rails/jquery-ujs/raw/master/src/rails.js
+}
+
+function jquery_install {
+  about 'download jquery.js into public/javascripts'
+  group javascripts
+
+  if [ -z "$1" ]
+  then
+      version=$JQUERY_VERSION_NUMBER
+  else
+      version="$1"
+  fi
+  curl -o public/javascripts/jquery.js "http://ajax.googleapis.com/ajax/libs/jquery/$version/jquery.min.js"
+}
+
+function jquery_ui_install {
+  about 'download jquery_us.js into public/javascripts'
+  group javascripts
+
+  if [ -z "$1" ]
+  then
+      version=$JQUERY_UI_VERSION_NUMBER
+  else
+      version="$1"
+  fi
+
+  curl -o public/javascripts/jquery_ui.js "http://ajax.googleapis.com/ajax/libs/jqueryui/$version/jquery-ui.min.js"
+}