BREAKS SOURCE RELEASE BUILD
Some of the required files were not getting copied while
performing 'make dist' and hence the build failed for
the created distribution source.
Added the missing files to Makefile.am.
Problem: libedit is a very pure-ASCII oriented library,
and it is not aware of extended (0x80..0xFF) or even multi-byte
characters. It considered such characters as non-printable
and didn't allow to input them.
Fix: make libedit think that all bytes >= 0x80 are printable.
