changed olLayer as a property

gulpfile.js

lib/layers/LayerBase.js

lib/layers/LayerBaseVector.js

lib/layers/LayerBaseXyzTile.js

lib/layers/LayerEsriMapServer.js

src/layers/LayerBase.js

src/layers/LayerBaseVector.js

src/layers/LayerBaseXyzTile.js

src/layers/LayerEsriMapServer.js

test-build/compare-test.js

test-build/compare-test.js.map

test-build/export-test.js

test-build/export-test.js.map

test-build/legend-test.js

test-build/legend-test.js.map

test-build/slider-test.js

test-build/slider-test.js.map

test-build/test-bundle.js

test-build/test-bundle.js.map

test-html/export-test.html