Add more precision to the standard XMLs

[bc118]

This is not urgent or a priority, more of a note. This is important for precision when converting units and rounding in the different writer outputs.

Add more digit precision to the input units in the foyer XMLs (oplsaa and trappe-ua). The values are slightly off when rounding and converting units, most notably in the angle angles (in degrees). For example, 109.4699 should be 109.47