binary addons: only read the URL and revision of an addon if it is built
cmake: use separate_arguments() instead of string(REPLACE) to split a string into a list
binary addons: add platforms.txt to specify the platforms an addon can be built for
cmake: use ${CMAKE_COMMAND} instead of "cmake"
[rbp] Make gui limit default to 720 when memory is limited

On a 256M Pi, it's safest to default to 720p gui as memory is quite limited.
[POSIX] fix mount regexp on FreeBSD

same as OSX
Merge pull request #5125 from Montellese/binary_addons_plat

binary addons: add platforms.txt to be able to control on which platforms an addon can be built
Merge pull request #5094 from popcornmix/limitres

[rbp] Make gui limit default to 720 when memory is limited
Merge pull request #5159 from Fneufneu/mount_freebsd

[POSIX] fix mount regexp on FreeBSD
[omxplayer] Use macros to reduce diffs with dvdplayer
[omxplayer] Use names closer to dvdplayer
[omxplayer] GetAbsoluteClock like dvdplayer
[omxplayer] Cosmetic: Copy formatting from dvdplayer
[omxplayer] Update master clock changes from dvdplayer
[omxplayer] Update to dvdrefactor
[players] Move Step implementation into PlayerVideo
[players] Make methods protected
[players] Remove unused functions
[players] constify functions
[players] Add plumbing for missing methods for consistency