systemdeps.h added a new defined case __ARM__ to clear the POST_PACKED_STRUCTURE for ARM compilation.

Downgraded eigen3 and sox version requirements for building iio.
Switched to using IIOMMap to access the IIO subsystem.
Added the overloaded methods for JackIIODriver::Attach, JackIIODriver::Detach, JackIIODriver::Read and JackIIODriver::Write.
Rewrite the JackIIODriver.C code to work properly.

systemdeps.h

@@ -120,7 +120,7 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
 #endif /* __APPLE__ || __linux__ || __sun__ || sun */
 
-#if defined(__arm__)
+#if defined(__arm__) || defined(__ARM__)
     #undef POST_PACKED_STRUCTURE
     #define POST_PACKED_STRUCTURE
 #endif /* __arm__ */