replaced figures, added references to figures that aren't hardcoded

changed bibliographystyle to ieeetr so that the references are numbered
 in order of appearance instead of alphabetically.
Merge branch 'IMR_2013' of github.com:davidom/Optimal_Edge_Grid into IMR_2013

Conflicts:
	Discrete_Curvature_Approximation.tex
	Error_Bounds.tex
	Refinement_via_Arc-Length_Deficit.tex