Document text query language

[bestchai]

The syntax and semantics of the text query language should be explained to the user.

There needs to be two sets of explanations: a longer, more detailed version for the wiki and a very brief "quickstart" guide that will go directly in the shiviz app.

The detailed description should be fairly detailed and should explain all the features of the language, but it shouldn't be super-formal (i.e no need to specify the syntactic grammar of the language in EBNF, etc).

[Issue created by pqperry: 2014-08-02] [Last updated on bitbucket: 2014-08-26]