Add rebar.config and travis-ci config options
fix travis to just use rebar
Fixed makefile for dialyzer
create halt/1

will cause process to exit with the supplied reason, in case you wish to "Let it crash"

fix #30
First version of new interface

We have included two different databases based on dict and ETS. The
default is to use dict. While there is no longer any general server
interface we still have a simple erlog shell.
Merge branch 'develop' into new-interface
update readme to match @rvirding's new API
fix some of the types
Add fast length/2 to lists library
Rename library modules to erlog_lib_???

This will make the disctinction between core modules and library
modules much clearer.
Missed changing a few references from erlog_dcg to erlog_lib_dcg
pointers to stack overflow and erlog_server
Merge pull request #39 from zkessin/readme

Readme
Add line specifying emacs prolog mode in example files
Make arg/3 generate values on backtracking as well

Also limited unnecessary deep dereferencing in functor/3 and
atom_chars/2.
Add BIP atom_codes/2
Optimise length/2

Also change name of make_vars/2 to make_var_list/2.
Merge new-interface
updated test to new format
remove cover comamnd that was commented out