added support for replaceable/default parameters for remote WMS tile store + WMTS
added description of new parameter defaulting/replacing options for remotewms tile stores
added implementation of parameter passing to remote WMTS tile store (GetTile only)
added description of parameter replacement/defaulting for remote WMTS tile stores
fixed compile errors
fixed adding of remote WMTS extra params
Merge pull request #65 from occamlabs/remotewms-tilestore-parameter-pass

WMTS -> remote WMS/WMTS tile store parameter passing