[PATCH] key=value operator for search action

[jttt]

New operator for search action with following semantics:

tagName=tagValue - matches tag with key=tagName and value=tagValue. It's exact match, no partial matches or special key types as with ':' operator
tagName=* - key with any value
tagName= - tagName doesn't exists
*=tagValue - any tag with value = tagValue
*=* - any tag
*= -untagged

The main difference between '=' and ':' is that ':' has some special keys that act differently (type,user,id,modified,...) and ':' is doing fulltext search while '=' is for exact match.

Some of '=' operator features can be emulated by ':' with regular expressions, for example ^type$:^route$, but using regual expression for such a simple thing is not quite comfortable and not everybody knows regual expressions.

Other features can't be afaik emulated, for example "tagName=" (meaning tag with tagName doesn't exist)

[stoecker]

In r1641.