[ftdump] Print CID-keyed font properties if available.

* src/ftdump.c

(FT_CID_MAX): New macro.

(usage): Mention the CID coverage in `-c' and `-C'
options.

(Print_UInt_Range): New function to print 2 numbers
with a separator if needed.

(Print_CIDs): New function to print the implemented
CIDs in a compressed syntax.  If a case
`gid_N < gid_M && CID_N > CID_M' is found, ftdump
aborts and guide the user to file the issue.

(Print_ROS_From_Face): New function to print the
Registry, Ordering, and Supplement of the CID-keyed
fonts, if available.  If `-c' or `-C' option is
given, Print_CIDs() is invoked.

(main): Invoke Print_ROS_From_Face().