Added info on downloading dependencies to readme

Author: LRFLEW

README.md

@@ -11,3 +11,7 @@ To build this project, you need two libraries:
 
  * [Qt 5](http://www.qt.io/download-open-source/). Note that Qt 4 will not work
  * [libarchive 2 or 3](http://www.libarchive.org). The upcoming version 4 won't work currently
+
+For OS X, it is recommended that you install both dependencies with brew using `brew install qt5 libarchive`, but leave both of them keg-only. It's recommended that you download and use [Qt Creator](http://www.qt.io/download-open-source/#section-6) as your IDE.
+
+For Linux, search your distro's package manager for libarchive and Qt5. If you're using Ubuntu, follow [these instructions](https://wiki.qt.io/Install_Qt_5_on_Ubuntu) for getting Qt5 installed.