styles for unicode borders are merged (PostgreSQL 9.5)

Following feature is less important for performance, but for somebody can be important for aesthetic reasons - now you can use a styles for unicode table borders. Possible styles are only two, but you can set a border, header and column style. It is a 6 combinations. Next you have a 3 styles for borders generally - so it together 18 possible combinations of psql table output:

postgres=# \pset unicode_header_linestyle double 
Unicode border linestyle is "double".
postgres=# \pset linestyle unicode 
Line style is unicode.
postgres=# \l
                                  List of databases
   Name    │  Owner   │ Encoding │   Collate   │    Ctype    │   Access privileges   
═══════════╪══════════╪══════════╪═════════════╪═════════════╪═══════════════════════
 postgres  │ postgres │ UTF8     │ en_US.UTF-8 │ en_US.UTF-8 │ 
 template0 │ postgres │ UTF8     │ en_US.UTF-8 │ en_US.UTF-8 │ =c/postgres          ↵
           │          │          │             │             │ postgres=CTc/postgres
 template1 │ postgres │ UTF8     │ en_US.UTF-8 │ en_US.UTF-8 │ =c/postgres          ↵
           │          │          │             │             │ postgres=CTc/postgres
(3 rows)

postgres=# \pset border 0
Border style is 0.

postgres=# \l
                            List of databases
  Name     Owner   Encoding   Collate      Ctype      Access privileges   
═════════ ════════ ════════ ═══════════ ═══════════ ═════════════════════
postgres  postgres UTF8     en_US.UTF-8 en_US.UTF-8 
template0 postgres UTF8     en_US.UTF-8 en_US.UTF-8 =c/postgres          ↵
                                                    postgres=CTc/postgres
template1 postgres UTF8     en_US.UTF-8 en_US.UTF-8 =c/postgres          ↵
                                                    postgres=CTc/postgres
(3 rows)


postgres=# \pset border 2
Border style is 2.
postgres=# \l
                                   List of databases
┌───────────┬──────────┬──────────┬─────────────┬─────────────┬───────────────────────┐
│   Name    │  Owner   │ Encoding │   Collate   │    Ctype    │   Access privileges   │
╞═══════════╪══════════╪══════════╪═════════════╪═════════════╪═══════════════════════╡
│ postgres  │ postgres │ UTF8     │ en_US.UTF-8 │ en_US.UTF-8 │                       │
│ template0 │ postgres │ UTF8     │ en_US.UTF-8 │ en_US.UTF-8 │ =c/postgres          ↵│
│           │          │          │             │             │ postgres=CTc/postgres │
│ template1 │ postgres │ UTF8     │ en_US.UTF-8 │ en_US.UTF-8 │ =c/postgres          ↵│
│           │          │          │             │             │ postgres=CTc/postgres │
└───────────┴──────────┴──────────┴─────────────┴─────────────┴───────────────────────┘
(3 rows)

postgres=# \pset unicode_border_linestyle double 
Unicode border linestyle is "double".
postgres=# \l
                                   List of databases
╔═══════════╤══════════╤══════════╤═════════════╤═════════════╤═══════════════════════╗
║   Name    │  Owner   │ Encoding │   Collate   │    Ctype    │   Access privileges   ║
╠═══════════╪══════════╪══════════╪═════════════╪═════════════╪═══════════════════════╣
║ postgres  │ postgres │ UTF8     │ en_US.UTF-8 │ en_US.UTF-8 │                       ║
║ template0 │ postgres │ UTF8     │ en_US.UTF-8 │ en_US.UTF-8 │ =c/postgres          ↵║
║           │          │          │             │             │ postgres=CTc/postgres ║
║ template1 │ postgres │ UTF8     │ en_US.UTF-8 │ en_US.UTF-8 │ =c/postgres          ↵║
║           │          │          │             │             │ postgres=CTc/postgres ║
╚═══════════╧══════════╧══════════╧═════════════╧═════════════╧═══════════════════════╝
(3 rows)

postgres=# \pset border 1
Border style is 1.
postgres=# \pset unicode_column_linestyle double
Unicode column linestyle is "double".
postgres=# \l
                                  List of databases
   Name    ║  Owner   ║ Encoding ║   Collate   ║    Ctype    ║   Access privileges   
═══════════╬══════════╬══════════╬═════════════╬═════════════╬═══════════════════════
 postgres  ║ postgres ║ UTF8     ║ en_US.UTF-8 ║ en_US.UTF-8 ║ 
 template0 ║ postgres ║ UTF8     ║ en_US.UTF-8 ║ en_US.UTF-8 ║ =c/postgres          ↵
           ║          ║          ║             ║             ║ postgres=CTc/postgres
 template1 ║ postgres ║ UTF8     ║ en_US.UTF-8 ║ en_US.UTF-8 ║ =c/postgres          ↵
           ║          ║          ║             ║             ║ postgres=CTc/postgres
(3 rows)