Merge pull request #3058 from chrisfsmith/feature/textastic

Adding Textastic plugin (OS X only)

plugins/textastic/README.md

+## textastic
+
+Plugin for Textastic, a text and code editor for Mac OS X 
+
+### Requirements
+
+ * [Textastic](http://www.textasticapp.com/mac.html)
+
+### Usage
+
+ * If `tt` command is called without an argument, launch Textastic
+
+ * If `tt` is passed a directory, cd to it and open it in Textastic
+
+ * If `tt` is passed a file, open it in Textastic

plugins/textastic/textastic.plugin.zsh

+#
+# If the tt command is called without an argument, launch Textastic
+# If tt is passed a directory, cd to it and open it in Textastic
+# If tt is passed a file, open it in Textastic
+#
+function tt() {
+    if [[ -z "$1" ]]
+    then
+        open -a "textastic.app"
+    else
+        open -a "textastic.app" "$1"
+        if [[ -d "$1" ]]
+        then
+            cd "$1"
+        fi
+    fi
+}