[epg] handle <onback> just like every other control
[pvr] no need to handle ACTION_NAV_BACK and ACTION_PREVIOUS_MENU in GUIWindowPVRCommon - they're handled in GUIMediaWindow already
[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
[coreSubs] option to search by manually entering search string
CharsetDetection: add ConvertHtmlToUtf8() and helper functions
ConvertHtmlToUtf8() detects HTML charset and convert HTML to UTF-8
CharsetConverter: add systemToUtf8
CharsetDetection: add "ConvertPlainTextToUtf8()"
FileUtils: add file type detection based on Mime-type
ScraperUrl: detect and use charset even if web server don't report it
[rbp] Avoid resizing 1080p fanart

Currently all re-encoded jpgs are resized to multiples of 16 widths and heights.
This causes additional blurring, especially for 1080p (which becomes 1088), as well as subtle aspect ratio errors.

Remove the alignment clamping, and fix up the heights/strides where needed
[rbp] We require the pixels in non-reencoding texture caching

If the direct texture reencode path fails, we do a seperate jpeg decode then encode path, which always fails as the pixels are not available.
Make sure we set the require pixels flag in this case
Merge pull request #3816 from amet/manualSearch

[coreSubs] option to manually entering search string
Merge pull request #3968 from popcornmix/require_pix

[rbp] We require the pixels in non-reencoding texture caching
Merge pull request #3958 from jmarshallnz/epg_nav_back

[epg] handle <onback> just like every other control
Merge pull request #3796 from Karlson2k/html_charset_detecton_01

Properly detect HTML charset even if not reported by server
Merge pull request #3969 from popcornmix/resize_align

[rbp] Avoid resizing 1080p fanart
[3D] Support switching to 3D resolutions

Include matching 3D flags (SBS/TAB) in the score of a resolution to switch to, to enable switching to 3d modes.
Also remove the old code that treated 3D modes differently when assigning a score.

I've also added a small weight to higher multiples of the desired framerate, so if display supports 30, 60 and 120Hz
and the video is 30fps then 30 will now be chosen rather than 120. This reduces the overhead of rendering the gui.
[confluence] Use animated gif as a cheaper working spinner
[rbp/omxplayer] Do we need discontinuity handling?

So far I've not seen what this is needed for and it does cause problems for some files.
h264_parser: Initialize the h264dsp context in the parser as well

Each AVStream struct for an H.264 elementary stream actually has two
copies of the H264DSPContext struct (and in fact all the other members
of H264Context as well):

((H264Context *) ((AVStream *)st)->codec->priv_data)->h264dsp
((H264Context *) ((AVStream *)st)->parser->priv_data)->h264dsp

but only the first of these was actually being initialised. This
prevented the addition of platform-specific implementations of
parser-related functions.

Signed-off-by: Martin Storsjö <martin@martin.st>