Replacing useragentUtils with uadetector library

* UserAgentUtils library is NOT being published to
Maven Central. This is preventing us from deploying
to Maven Central. So switching from UserAgentUtils
to UADetector library which also helps in parsing
User Agents of browsers and is also available in 
Maven central.
Tweaks to the previous commit
Tweaks for SeLion Grid:
* Extraction:
  * Added dependency for the commons-compress library for extracting artifacts
  * Leveraged the ArchiveStreamFactory to deal with .zip,.tar and .tar.bz2
  * Made extraction specific to platforms

* Download:
  * Tweak downloads as per the platform
  * Refactored GridAutoUpgradeServlet to display fields as per the platform

* Fixed IndexOutOfBoundException in AbstractProcessHandler
* Removed the .json template files that had the names of artifacts and its relevant
  extracted binary name. This adds overhead in maintaining the artifact names in two places.
* Added unit tests
* Addressed review comments
* Changed the URL and checksum for Linux artifacts to x86 platform
* Changed the executable name for IEDriverServer to lowercase to maintain uniformity in comparison
* Separating the FileExtractor to a separate class to handle extraction
Minor code tweaks

* Added the license header for some classes.
* Ripped out EmailAssistant class which is NOT being
used.
* Reduced visibility of FileExtractor to a package
visible class and added a private constructor
Re-factoring of LocalSelendroidNode and LocalIOSNode classes. 

* Extracted common methods to an abstract super class.
* Reduced visibility of LocalSelendroidNode to package visible