[dist] add missing files
sort error messages by its code

Now the order is the same as oniguruma.h.
testpy.py: support error tests

E.g.:
  n("[", "", err=-103)
update documents and version number (5.14.1)

* Update the version number to 5.14.1.
* Update LTVERSION to 5:1:0. (Issue #37)
move prototype

Move the prototype of onig_print_compiled_byte_code() from regexec.c to
regint.h.
prototypes were changed for Ruby 1.9+

Follow the changes.
comment out unused variables
update makefiles
Merge tag 'Onigmo-5.14.1' into ruby-2.x

Onigmo 5.14.1