modified:   sumMetric.py

	new file:   Tests/segment1sc
	new file:   Tests/segment2sc
	new file:   Tests/segment3sc
	modified:   lg.py
	modified:   testlg.py

led to negative error measures.

Modified lg2txt.py to support mapping arbitrary symbols with certain relationships; updated mathMLMap.csv mapping file.

Additions and corrections to symbol and structure maps identified while creating the 2013 RIT-side test data set.

Added lost changes from previous commits; created default mappings for symbols and relationships, updated translation file.

Updated evaluate (keep rather than delete files; don't generate .dot/.pdf by default); symbol counts added to sumDiff.py