Convert to use Apache License, Version 2.0
Create Erlog start file erlog
Add block comments of type /* ... */
Fix compilation errors, now rebar compatible.
Add missing \== operator.
Fix user_guide typos.
Add BIPs atom_chars/2 and atom_length/2

After a suggestion by Sean Cribbs.
Merge branch 'develop'
Improve Makefile to do conditional compilation
Break out BIPs into separate module

The control and database BIPs are left in the interpreter as they are
really part of it.
Quote atoms when needed, must special case ,

The quoting is too simple and cannot handle characters in atom whcih
need to be backquoted.
Normalised io functions to have an xxx1 version to return an iolist
Move DCG code and predicates to separate module
Implement the erlog server as a gen_server
Move lists predicates to separate module
Make add_compiled_proc and add_built_in take functor
Fix token in syntax_error in all_read/2

Also took the chans to change the 'dot' token to a '.'.
Add equivalence of ./2 and lists
Move file (re)consulting into erlog_file
Remove user_pl.erl as it has been subsumed by erlog_lists