• find_arduino_library was fixed, it falsely included local directory as a library, even though it was not compatible with Arduino library structure. Now it works as is written in the comment.

A Arduino library is a folder that has the same name as the include header.
For example, if we have a include "#include <LibraryName.h>" then the following
directory structure is considered an Arduino library:

LibraryName/
|- LibraryName.h
`- LibraryName.c

• make_arduino_library was fixed, it didn't return include path for libraries that had a cmake target already created.