MainFrame: adjust the fullscreen size on move
MainFrame: adjust the fullscreen size on open

Fixes #4082
MainFrame: tweak overridden Alt key behaviour

When menubar has focus, we don't receive WM_SYSKEYDOWN messages, only
WM_SYSKEYUP messages. Overriding only show menubar behavior is
reasonable compromise.
Stop mouse hider when entering menu modal loop

We don't receive WM_MOUSELEAVE message until the loop exits
otherwise
Controls: properly remove unused hide ticks

Otherwise we may stay subscribed to periodic timer without a need to
PPageFullscreen: dirty when changing hide policy
Don't read media flags in "delay show not loaded"

They can be whatever
Seekbar: fix possible memory leak
PlayerBar: better way of detecting context menu
PlayerBar: more strict access specifiers
MainFrame: change zorder after reposition

Refs #3980, #4037
MainFrame: show menu after reposition

Refs #4004
Don't MoveVideoWindow() during fullscreen toggle

Refs #4004
MainFrame: send WM_MOUSEWHEEL to child view

Fixes #4070
Update frame when entering fullscreen

Refs #3987
Update Changelog.txt
DVBSub: Improve error checking during parsing.
Updated LAV Filters to 0.60.1-65-ddc46e6 (custom build based on 0.60.1-60-445393e)

Important change:
 - LAV Video: Fix artifacts on some H264 streams with both software and DXVA decoding (reported upstream as https://trac.ffmpeg.org/ticket/3386).
Lite builds: Fix a minor inconsistency regarding the output directory.

Lite debug builds use "mpc-hc_x??_Debug Lite" while release builds always used "mpc-hc_x??" for both normal and lite builds.
Fix: x86 and x64 versions conflicted over file associations.

4f465cf8b81f1da800b1bfc57cc48e317d24fbb5 was incomplete for Vista+.

This commit fixes #4064.