Datasette 0.21: New _shape=, new _size=, search within columns

New JSON _shape= options, the ability to set table _size= and a mechanism for searching within specific columns.

• Default tests to using a longer timelimit

  Every now and then a test will fail in Travis CI on Python 3.5 because it hit the default 20ms SQL time limit.

  Test fixtures now default to a 200ms time limit, and we only use the 20ms time limit for the specific test that tests query interruption.

  This should make our tests on Python 3.5 in Travis much more stable.

• Support _search_COLUMN=text searches, closes #237

• Show version on /-/plugins page, closes #248

• ?_size=max option, closes #249

• Added /-/versions and /-/versions.json, closes #244

  Sample output:

  {
    "python": {
      "version": "3.6.3",
      "full": "3.6.3 (default, Oct  4 2017, 06:09:38) \n[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.37)]"
    },
    "datasette": {
      "version": "0.20"
    },
    "sqlite": {
      "version": "3.23.1",
      "extensions": {
        "json1": null,
        "spatialite": "4.3.0a"
      }
    }
  }
  

• Renamed ?_sql_time_limit_ms= to ?_timelimit, closes #242

• New ?_shape=array option + tweaks to _shape, closes #245

  • Default is now ?_shape=arrays (renamed from lists)
  • New ?_shape=array returns an array of objects as the root object
  • Changed ?_shape=object to return the object as the root
  • Updated docs

• FTS tables now detected by inspect(), closes #240

• New ?_size=XXX querystring parameter for table view, closes #229

  Also added documentation for all of the _special arguments.

  Plus deleted some duplicate logic implementing _group_count.

• If max_returned_rows==page_size, increment max_returned_rows - fixes #230

• New hidden: True option for table metadata, closes #239

• Hide idx_* tables if spatialite detected, closes #228

• Added class=rows-and-columns to custom query results table

• Added CSS class rows-and-columns to main table

• label_column option in metadata.json - closes #234