refine some declarations in header files

Remove duplicate declarations and move some other declarations to
addrtoname.h where they belong.
NDOize timed decoder
improve previous NDO conversions
NDOize some generic code
coordinate ascii_print() prototypes for MSVC

ascii_print() has conflicts between prototype and implementation. MSVC
doesn't allow adding a register modifier just like that.
Add missing break - thanks to Coverity for finding this one.
Check for truncation in strings.

Found by Coverity.