err and warn are BSD format but they are not recommended by library
developers. However their consiseness is useful!
The solution is to use some macros that create xerr etc which then
just map to the error() function. The next problem is error() uses
program_invocation_name so we set this to program_invovation_short_name
This is a global set but seems to be the convention (or at least errors
are on the short name only) used everywhere else.
The utility library is for functions which are shared in commands,
but that does not belong to libproc-ng. The first function is a
wrapper for strtol that performs error checking, and exists if such
happen.
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
