Removed limit type restriction in `getLookupRange()`.
Removed limit type restriction in `getLookupRange()`.

This checking is already done by functions computing infinity and next, and it
also didn't allow strings, which are supported.  Some hints on condition syntax
have also been updated.


git-svn-id: 92c705c98a17f0f7623a131b3c42ed50fcde59b4@1862 1b98710c-d8ec-0310-ae81-f5f2bcd8cb94

cpcloud/PyTables,jennolsen84/PyTables,gdementen/PyTables,rabernat/PyTables,tp199911/PyTables,jack-pappas/PyTables,rabernat/PyTables,FrancescAlted/PyTables,rdhyee/PyTables,jack-pappas/PyTables,FrancescAlted/PyTables,tp199911/PyTables,jack-pappas/PyTables,gdementen/PyTables,joonro/PyTables,FrancescAlted/PyTables,rabernat/PyTables,mohamed-ali/PyTables,avalentino/PyTables,avalentino/PyTables,andreabedini/PyTables,PyTables/PyTables,tp199911/PyTables,andreabedini/PyTables,jack-pappas/PyTables,gdementen/PyTables,dotsdl/PyTables,mohamed-ali/PyTables,rdhyee/PyTables,andreabedini/PyTables,mohamed-ali/PyTables,jack-pappas/PyTables,PyTables/PyTables,cpcloud/PyTables,jennolsen84/PyTables,cpcloud/PyTables,andreabedini/PyTables,jennolsen84/PyTables,dotsdl/PyTables,joonro/PyTables,mohamed-ali/PyTables,dotsdl/PyTables,dotsdl/PyTables,rabernat/PyTables,cpcloud/PyTables,tp199911/PyTables,PyTables/PyTables,gdementen/PyTables,avalentino/PyTables,rdhyee/PyTables,jennolsen84/PyTables,joonro/PyTables,joonro/PyTables,rdhyee/PyTables