Fixed an error message glitch, %s is not used by stop()
Fix printing of prereleases, need a separating dash
Use smarter ||, because R || converts to logical

Instead of returning the argument itself.
Fix a compare_pre indexing bug
Fix a compare_identifiers self/private bug
Need to use C locale for string sorting
Fix a compare_identifiers bug, -1L instead of 1
Fix a cmp bug for "==" and loose = TRUE
Better error message for non-string objects in semver$new