btsync: changed the method by which the btsync application is downloaded.  When using plugin XML FILE attribute, the file is reported by installplg as being downloaded sucessfully, however no resultant file is created in the plugin subdirectory. Modifled code to download the application during the installation script instead of the XML FILE attribute. Code checks for existing copy of the application in btsync plugin directory and installs if found, alternatively downloads from btsync url to /tmp followed by storing a locally saved copy inside the btsync plugin subdirectory to save downloading upon each subsequent plugin installation. Plugin version bump to 2.2