Committed to semantic versioning

as prompted by #365, #430, #447 and a thread on the google group.
- split version bumping out of generateSingleHeader script
- separate scripts for bumping each version component
- "build" number only incremented for "develop" builds

scripts/majorRelease.py

@@ -0,0 +1,9 @@
+from  __future__ import  print_function
+from releaseCommon import Version
+
+v = Version()
+v.incrementMajorVersion()
+v.updateVersionFile()
+v.updateReadmeFile()
+
+print( "Updated Version.hpp and README to v{0}".format( v.getVersionString() ) )