To avoid conflicts with previous libfprint version and make sure that the
target version is the correct one (plus to allow parallel install in some
distros), let's use a versioned naming for the library keeping the abi
version in sync.
Fixes#223
Meson files are normally using 4-spaces to indent and functions use first
parameter on the same line while others at next indentation level, not
following the parenthesis indentation.
So adapt libfprint to follow the meson standard.