DVDSubtitleStream: better detect stream encoding and optimization
Use BOM detection for all supported charsets, not only UTF-8 and UTF-16LE
Do not double convert subtitle->wstring->UTF-8. Use direct conversion subtitle->UTF-8
additionally: CharsetConverter: subtitleCharsetToW -> subtitleCharsetToUtf8
[spectrum] cosmetic: Use static where appropriate
[rbp] Remove PiAudio engine
[rbp] Add PiAudio sink
[spectrum] Draw spectrum as a single object

glDrawElements is called 256 times per frame, once for each bar. It is more efficient to batch up larger blocks.
This change draws the specrum with a single glDrawElements call.

Looking at visualisation in full screen mode, it used to top out at 75 fps. With this PR it can hit 125 fps.
fixed: add GIF as known header to cximage.
changed: pass detected image mimetype further down to avoid a second lookup.
imagefactory: removed unused method.
Support uClibc compilation

partly based on aports from Alpine Linux:
http://code.ohloh.net/file?fid=Up3lAbVglPtyupfNPazFHQYMKM8&cid=Sr-nRbkkE8E&s=&fp=302485&mp=&projSelected=true#L0
[epg] handle <onback> just like every other control
[README] remove libhal* add libnfs
[pvr] no need to handle ACTION_NAV_BACK and ACTION_PREVIOUS_MENU in GUIWindowPVRCommon - they're handled in GUIMediaWindow already
changed: added another GetMimeType for urls and use it in the imagefactory if no mimetype is set.
[pvr] only handle ACTION_NAV_BACK in GUIWindowPVRRecordings if there's a parent directory to go to, else drop down to the base class as the action will be handled by the window system
[info] don't URL decode paths and filenames - pass them as-is (save user/pass detail). Fixes #13823
Confluence Icon refresh

Everything else the same and was shamelessly duplicated into vectors.

The point was not to cover any significant portions of the art while
keeping original elements of the design intact.

Also saved 10KB of size without quality loss.).

Ribbon removed as per ronie comment.
Merge pull request #3955 from uNiversaI/icon

Confluence Icon refresh
[masterlock] check master lock when going to the skin settings window. Closes #14070
Merge pull request #3947 from wsoltys/imagemimetype

fixed: loading of images from urls which don't have an extension...
Merge pull request #3961 from jmarshallnz/check_masterlock_skin_settings

[masterlock] check master lock when going to the skin settings window.