Qt4 - tracks detection is splitted from the other functions. Fix the "fullscreen button not showing" bug in some cases.

Qt4 - Fix compilation

Qt4 - Simple Preferences, audio: you expect to deal with % for the volume not abstract values from 0 to 1024... Added a label for that.

Qt4 - Update check every x days. Put it in the preferences, and in the privacy Dialog (may be useless on the privacy dialog ).

Qt4 - Launch the update every x days ( x being 14 days by default ). Check done just before the exec(). part 1.

    declare unused parameters in callbacks as void
    use size_t
    xml/xtag.c: comment dead code
    freetype: use mdate() instead of time(), remove unused parameter from UnderlineGlyphYUVA()
    notify/growl: factorize NotifyGrowl()

    avi/avi_HeaderAdd_str{h,f}(): removes unused parameter
    mp4/Convert{SUBT,AVC1}() GetD263Tag() Get{Text,Vide}Box(): same
    mpeg/ts/BufferChainClean(): same
    ogg/OggCreate{Header,Footer}(): same

    declare unused parameters in vlc callbacks as void
    deinterlace/RenderX() & motionblur/Copy(): remove unused argument

    rtp: add the prototype for rtp_packetize_h264_nal()
    transcode: transcode_{spu,audio}_close(): removes unused argument
    mosaic_bridge: video_del_buffer(): removes unused argument

removes unused arguments

    use size_t instead of int to represent sizes
    removes unused parameters from:
        block_BytestreamInit()
        mpeg4_audio/LOASSyncInfo()
        cinepak/cinepak_Getv1()
        speex/SendPacket()
        subsass/ParseColor()
        ffmpeg/postprocess/InitPostproc() & PostprocPict()
        dvbsub/YuvaYuvp() & encode_pixel_line_{2,4,8}bp()
        faad/DoReordering()

vlc_block_helper.h:
    use size_t, removes unused parameter from block_BytestreamInit()

struct filter_t:
    removes unused parameters from pf_picture_link() & pf_picture_unlink()
    
cmml: fix a segfault (p_item isn't an input item, despite the name) present for some months, proving that nobody did use that code ?

- fix qmax/qmin if statements                                                                                  
- if user requests certain bitrate, set defaults to qmax=51,qmin=10 if
  user hasn't defined them otherwise. Should help normal user to get
  bitrate he/she requests.