Remove friendship
Factorisation of CoverArt
Reduction of class footprints
virtual and protected correctness
Forward declaration when possible

It's useless and create bogus empty commands, that output ugly blank
lines and crap during login

--no-color / --color is a fine enough control

ManageSlider() -> ChangePosition(), now takes the position increment as (signed) argument
Don't show percentage of media in Position (elapsed/total already show this information)

factor out file/directory detection code
remove the need for {OPEN,SEARCH}_CHAIN_SIZE defines

remove code to workaround lack of unicode support

Also statically allocate open and search buffers

align 'case' on the same level than 'switch'
use an inline function to switch boxes

Comment out all messages box code
Factorize Eject()
Replace break/goto in HandleKey() by return
Draw immediately on start of interface (avoid flicker)
fix Playlist race condition in Run()
Remove pointless comments

remove unused intf_sys_t members
remove useless assignements
use C99 for(;;)
fix a double free when not using ncursesw
use sizeof instead of strlen() when possible
use var_GetInteger() instead of var_Get()
use calloc() to allocate intf_sys_t and remove assignements which set memory to 0

Split some functions

factorize

Remove braces around a single statement
Merge some comparisons
"( a )"             -> "(a)"
"if(x)"             -> "if (x)"
"if (x == NULL)"    -> "if (!x)"
"if (x != NULL)"    -> "if (x)"

ReadDir: Invert logic to have less indentation:
{
    if( a )
        x();
    else
        y();
}
====>
{
    if( !a )
    {
        y();
        return;
    }

    x();
}

Remove most forward declarations
Also update copyright