Don't use zero energy frames in CMN calculation



git-svn-id: svn+ssh://svn.code.sf.net/p/cmusphinx/code/trunk/sphinxbase@12523 94700074-3cef-4d97-a70e-9c8c206c02f5
Fixes crash when fe is initialized with bad parameters



git-svn-id: svn+ssh://svn.code.sf.net/p/cmusphinx/code/trunk/sphinxbase@12524 94700074-3cef-4d97-a70e-9c8c206c02f5
More strict checking for input parameters



git-svn-id: svn+ssh://svn.code.sf.net/p/cmusphinx/code/trunk/sphinxbase@12526 94700074-3cef-4d97-a70e-9c8c206c02f5