[pvr] EPG hookdata: Return UniqueBroadcastID

Returns epgUid known by client instead unset data.
[ios64] - fixed offsets into the eventmem for arm64 - fixes bt keyboard cursor keys when compiled for arm64
correct codec names, MPEG is always written in upper-case
[cosmetic] add missing "l" in some comments
CHG: [mediacodec] switch to a surface render black list + backup AS
FIX: [linux] fix & optimize input device checking
Improved file buffering in CArchive.

CArchive already did some file buffering, but only on writes. Added the
equivalent code for reads. Also improved the write buffer case so that it
only ever issues sector-aligned writes (the read code does this from the
start). Shuffled various bits of code into the header file to squeeze a bit
more performance out of it.
linux: use CLOCK_MONOTONIC_RAW as this is not subject to NTP
[videodb] move AnnounceUpdate|Remove to statics
[announces] add 'transaction' attribution to OnUpdate, OnRemove if scanning.
drop unneeded tracking of database updating, using the 'transaction' attribute of OnUpdate/OnRemove instead
VDPAU: improve error handling
[build] enable gtest configure by default.
Merge pull request #4635 from FernetMenta/linux

linux: use CLOCK_MONOTONIC_RAW as this is not subject to NTP
Merge pull request #4638 from FernetMenta/vdpau2

VDPAU: improve error handling (ffmpeg 2.2)
Update README.boxeebox
Merge pull request #4640 from jmarshallnz/gtest_on

[build] enable gtest configure by default.
Merge remote-tracking branch 'upstream/master'
[gui] fix <hinttext> not being shown once unfocused/refocused
[addons] install from zip should install from the zip, not from packages/zip