Enhanced XDXF support (by soshial)
Update Simplified Chinese translation
Prevent compiler warning messages about OV_CALLBACKS_*
Dictd: Support extended Dictd format (--index-keep-orig) with 4 entries in the index

See the dictfmt man:

 --index-keep-orig
    When --utf-8 is specified  headwords  are  lowercased  and  non-
    alphanumeric  characters  are  removed  from it before saving to
    .index  file  in   order   to   simplify   the   search.    When
    --index-keep-orig  option  is  used fourth column is created (if
    necessary) in .index file, and  contains  an  original  headword
    which  is  returned by MATCH command.  This option may be useful
    to prevent converting " AT&T" to " ATT" or to keep proper  nouns
    with uppercased first letter.
Fix compilation failure on older Linux/GCC versions
One more fix for the compilation failures on older Linux/GCC
Add "DISABLE_INTERNAL_PLAYER" to .pro as an option to disable internal audio player (issue #356)
Dictd: Properly style the phonetic data and references/links