potential chirality issue

[fgrunewald]

There is one logic fault with regard to chirality in the current package. If the chiral atoms are all in one residue currently we build only one template. But if both chiralites are used we'd probably need to build 2. So the generate templates should also check that the improper diehdrals are equivalent and otherwise build 2 templates. This does not affect current test systems or the library polymers though.