[Rets-dev] RQL, Draft 4

[Dave Dribin]

Hi all,

Here is Draft 4 of RQL:

   <https://code.crt.realtors.org/svn/librets/rql/tags/draft-4/rql.html>
   <https://code.crt.realtors.org/svn/librets/rql/tags/draft-4/rql- 
bnf.txt>

The main changes are:

   * IS NULL and IS NOT NULL is allowed for all data types
   * Single-value lookups and multi-value lookups are now separate types
   * Java-style backslash escaping is now possible in quoted strings

-Dave