Corrected various hardcoded database table names

- Added an elemental_db setting to inter-server.conf (elemental table)
- Switched an instance of hardcoded `ipbanlist` to use the ipban_table
  setting; thanks to Takkun, related to issue #135
- Switched two instances of hardcoded `char` to use the char_db setting
- Added a TODO notice about the usage of the login table (on a side
  note, hardcoded) from the login server (related to issue #142)

Signed-off-by: Haru <haru@dotalux.com>
Changed Makefiles to avoid rebuilding targets if nothing was modified

To force a rebuild, it's still possible to use the -B flag of make, or
just run make clean beforehand.

Signed-off-by: Haru <haru@dotalux.com>