xlocale(3): Link man pages

[jlduran_gmail.com]

Summary

The following is the unified diff of the individual commits from GitHub Pull Request #621.

Essentially this is a followup of c889dd01b9ada00728601de06e8b087a8c751cbb.

From xlocale(3), this is just ctype_l. Others may need a similar treatment, but I'll wait for reviews of this one first.

[gbe]

LGTM

[bcr]

Can someone commit this? Thanks!

[gbe]

@bcr I take care of it, just have to write a more detailed commit message.