create_endemicity_status() suggestions

[luislvalente]

Two suggestions for create_endemicity_status(). In the new warning message to warn the user that some names were not found in the phylogeny:

• change "Species included in island_species not in phylogeny" to "The following names are included in island_species object but are not found in the phylogeny. So the data for these was not extracted. If you think the sample should be on the tree, please check if the string matches exactly." I suggest this change because "species" could be misleading, as the species may be found in a different tip.
• when there are many species not found on the tree, the warning message is truncated. It could be useful to see all the names that were not found.