[+] elcd: Add support listvoutput command

Signed-off-by: Anton Sergeev <Anton.Sergeev@elecard.ru>
[+] StbMainApp: Support controlling several video output modes

Signed-off-by: Anton Sergeev <Anton.Sergeev@elecard.ru>
[*] StbMainApp: Fix showing information and confirm message boxes on changing output resolution

Signed-off-by: Anton Sergeev <Anton.Sergeev@elecard.ru>
[*] StbMainApp: Fix start/stop keyThread

Signed-off-by: Anton Sergeev <Anton.Sergeev@elecard.ru>
[*] StbMainApp: Improve "toggle vfmt" function. Clean up source code.

Signed-off-by: Anton Sergeev <Anton.Sergeev@elecard.ru>
Merge branch 'vfmt'