small fix.


git-svn-id: svn://svn.code.sf.net/p/elmerfem/code/trunk@6768 04224531-1f84-46d8-96ce-875b9e37dce3
Corrected SegmentElementInside in ParticleUtils so that it correctly determines whether paricle is inside an element or not. Fix provided by Igor. 


git-svn-id: svn://svn.code.sf.net/p/elmerfem/code/trunk@6769 04224531-1f84-46d8-96ce-875b9e37dce3