fixed layer opacity for merge_method: composite
make tests not fail for different alpha_composite implementations
don't use cache sources with tiled_only when not supported by all sources
fixed docs markup for latex
use absolute urls multiapp index listing
fixed tests for multiapp
prevent caching of static legends for different scales
adding quadkey as file cache option
Merge pull request #82 from rduivenvoorde/quadkey_cache

adding quadkey as file cache option
handle featureinfo source responses with charset option in content-type

closes #50