This adds ol.parser.ogc.KML which can be used to read and write KML documents.
NetworkLinks are retrieved asynchronously.
Current caveats of the implementation are:
* LabelStyle not yet implemented. Missing support in renderers.
* When using shared structures the parser needs to be configured with
dimension 2.
* We need a better way to disable fill, currently we use opacity as a
workaround.
* We cannot really roundtrip documents, since some of the info is not
preserved in the ol structures. But we can write out most of the important
info.
getTile and the tileUrlFunc are functions of the source, so they do need to be passed the tile grid. The tile source knows its tile grid, and can get the projection's tile grid if it doesn't have a tile grid.
This massively reduces the number of temporary ol.TileCoord objects.
Previously an ol.TileCoord object was generated for every potentially
visible tile at the current zoom level and lower, every frame. This
commit eliminates all of those. Now new ol.TileCoord objects are only
allocated when a new tile is created.
This change removes all changes that were anticipated here for
WMS GetFeatureInfo handling, including the IWMS interface and
the goog.provide for 'ol.tilegrid'. I'll create a separate pull
request for WMS GetFeatureInfo eventually, taking into account
the suggestions from the discussion in #402.
With this change, url functions are called in the scope of the
source they are configured for. This allows us to simplify the
url function generation for WMS, using a more generic
createFromParamsFunction factory, and the source's new params
member.
Note that there is also a new url member for WMS sources. This
is the WMS base url (the first one in case there is an array of
urls for faster tile access). This can be used for accessing
other WMS services (especially GetFeatureInfo).
