avidemux and gcc6

[Dan Horák]

Hi,

because I wanted avidemux on F-24 I've spend some time to find the
missing gcc6 fixes, see the result in
http://fedora.danny.cz/avidemux-2.6.12-gcc6.patch
It now builds under F-24 mock.


Mostly cherry-picked from
https://github.com/mean00/avidemux2/commit/68df30b902540e6f299dc63ea3ae53b3d353cbe4
but also
https://github.com/mean00/avidemux2/commit/7dee579d3ac16d731898305d24bb771834ae0ce0
https://github.com/mean00/avidemux2/commit/6ad028d9f9caf929819c1afcb693611aade0af0b


		Dan