Rebuild Option

Top level build scripts do not build an external library if it is already compiled and installed. If you need to rebuild one of those libraries you have to use --rebuild-LIBRARY option.

This behaviour aims to decrease the amount of time required to re-build the FFmpegKit library.

PS: Note that adding --rebuild-LIBRARY option alone does not enable a library, only --enable-LIBRARY and --full options can do it. Additionally FFmpeg and FFmpegKit libraries are mandatory and always built, they do not support --reconf option.