Better monocyclic ring corrections in group additivity thermo estimation.

The previous implementation oddly made no attempt to account for ligands
when determining the ring correction to apply. The new version finds the
ring correction at each atom in the ring, and applies the one with the
largest H298, as this indicates larger ring strain. The new algorithm
works perfectly for fulvene.
Bugfix in removeCommentFromLine() when reading Chemkin files.

The previous implementation would add an extra newline character to lines
without comments.
Fixed bug in reading of uncertainty type from RMG-Java kinetics libraries.

The bug was that this code was interfering with the parsing of Chemkin
files by not giving the default value of AuncertaintyType.