Build instructions and linking proplems in Ubuntu 20.04

[jpmorrison]

• The build instructions reference old libgstreamer. I installed libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev
• It won't link in Ubuntu 20.04 because of many INLINE declarations
• To get it to build I tried #define INLINE in config.h
• libfreerdp-codec/color.c doesn't #include config.h added it there too

It builds now

/usr/bin/ld: ../../libfreerdp-codec/libfreerdp-codec.so.1.0.1: undefined reference to freerdp_color_make_bgr'
/usr/bin/ld: ../../libfreerdp-codec/libfreerdp-codec.so.1.0.1: undefined reference to freerdp_color_make_rgb' /usr/bin/ld: ../../libfreerdp-codec/libfreerdp-codec.so.1.0.1: undefined reference to freerdp_color_split_rgb'
/usr/bin/ld: ../../libfreerdp-codec/libfreerdp-codec.so.1.0.1: undefined reference to freerdp_color_split_bgr' collect2: error: ld returned 1 exit status make[2]: *** [client/test/CMakeFiles/freerdp-test.dir/build.make:93: client/test/freerdp-test] Error 1 make[1]: *** [CMakeFiles/Makefile2:1351: client/test/CMakeFiles/freerdp-test.dir/all] Error 2 make: *** [Makefile:152: all] Error 2