Fix build of playground/libs
Fix build of playground/libs

If you do not want your module to be build from playground/libs,
you should remove it from the playground/libs/CMakeLists.txt file.

Also added a conditional for Falcon to check if it really builds
(do not have it installed). For all Kross modules, we should use
some macro_log_feature.

CCMAIL: mathstuf@gmail.com
CCMAIL: flavio.castelli@gmail.com


git-svn-id: ec8dad496322030ce832d387f43d3d061c430ff7@997498 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

qlands/qjson,gentlefn/qjson,flavio/qjson,coolshou/qjson,cbranch/qjson-qmakefriendly,gentlefn/qjson,cbranch/qjson-qmakefriendly,seem-sky/qjson,flavio/qjson,coolshou/qjson,qlands/qjson,seem-sky/qjson,drizt/qjson,drizt/qjson