Added accent (dead) key support to syscons and kbdcontrol.

Added accent (dead) key support to syscons and kbdcontrol.

With a keymap with accent key definitions loaded to syscons, you press
an accent key followed by a regular letter key to produce an accented
letter.  Press an accent key followed by the space bar to get the
accent letter itself.

Code is based on the ideas and work by jmrueda@diatel.upm.es and
totii@est.is.

PR: i386/4016

- Added keywords for accent (dead) keys: dgra, dacu, dcir, dtil...
- Recognize accent map definitions.
<accent_map_definition> ::= <accent_key_name> <accent_char> <accent_map>
<accent_key_name> ::= dgra | dacu | dcir | dtil | dmac | dbre | ddot |
                      duml | dsla | drin | dced | dapo | ddac | dogo |
                      dcar
<accent_map> ::= <map_entry>
               | <map_entry> <accent_map>
<map_entry> ::= ( <regular_letter_char> <accented_char> )
- Use ioctls PIO_DEADKEYMAP and GIO_DEADKEYMAP to set and get the accent
  key map table in syscons.
- Made the output for the -L option more intelligible and look like
  initializers in kbdtables.h.
- Reorganized print functions in order to print the accent key map.