* Supports brackets
* Supports various operators:
	* <,<=,>,>=
	* == and = for equality.  Equality is case insensitive.
	* <> and != for inequality
	* like for SQLish pattern matching on strings.  _ matches exactly one character, and % matches zero or more characters.  For example "fish" like "fi%" is true.  The like operator is case insensitive.
	* relike allows for regular expression matches on strings.  The relike operator is case insenstive.  For example "Potato" relike "p[ota]+o".
	* + is for addition and string concatenation.
	* - does subtraction.
	* * will provide multiplication, and string repetition. (eg "x"*5 will evaluate to "xxxxx")
	* / provides division.
	* * and / have higher precidence than + and -.
	* not can be used to negate a subexpression.
	* - can be used as an unary minus.
	* The exists operator can be used to test if an attribute exists for an auction.  For example "exists buynow" will return true if the auction has a buynow set.
	* Numbers may start with a "$", and contain internal ,'s.
	* Fields must start with a letter (or _) and consist of alphanumerics.
	* AND and OR can be used to join subexpressions.
	* Ternary operator is supported ( condition ? ifTrue : ifFalse )
* Functions are supported
	* log
	* sqrt
* Precidence is used.  2+3*4 is 14, not 24.
* Strings must be quoted in " or ', and \ can be used to escape quotes.
* Mentioning a field will generally require the field to be present, unless
  the expression is negated with NOT.  Thus "not (buynow<10)" will include 
  auctions with no buynow, or where the buynow is greater or equal to 10, but
  not buynow's less than 10.  "buynow<5" will include all auctions that have
  a buynow less than 5, but will exclude everything that has no buynow.
* True and False are constants with the obvious value.
* You can define simple anonymous functions using the syntax { arguments => expression }
* Examples:
	bid*100/buynow > 90  	# Return all results that are within 10% of their buynow
	not (title like '%broken%') # Ignore all auctions who have "broken" in their title
	title relike '.*$?[0-9\,]\s+pw.*' # matches $120pw 10pw but not fish
	exists bedrooms # matches all auctions with a number of bedrooms
	bathrooms >= bedrooms/2 # matches all houses that have plenty of bathrooms
	(category = 'Electronics-photography/TVs/LCD/40+' or category = 'Electronics-photography/TVs/LCD/3039') and pi*(size/2)*(size/2) < 10000 # Because you can.
	log(buynow) / sqrt(size) < 1
	{ x => x + 1 }(1)
	{f x => x == 0 ? 1 : x * f(f,x-1)}({f x => x == 0 ? 1 : x * f(f,x-1)},5) > buynow