convert most images from png to jpg, update docs

client/html/View-Server_-_User-Guide_v1.1.0.pdf

client/html/user-guide/_images/arcgis_0.jpg

client/html/user-guide/_images/arcgis_1.jpg

client/html/user-guide/_images/arcgis_2.jpg

client/html/user-guide/_images/arcgis_3.jpg

client/html/user-guide/_images/arcgis_4.jpg

client/html/user-guide/_images/arcgis_5.jpg

client/html/user-guide/_images/arcgis_6.jpg

client/html/user-guide/_images/arcgis_7.jpg

client/html/user-guide/_images/arcgis_8.jpg

client/html/user-guide/_images/arcgis_9.jpg

client/html/user-guide/_images/wcs_qgis1.jpg

client/html/user-guide/_images/wcs_qgis2.jpg

client/html/user-guide/_images/wcs_qgis3.jpg

client/html/user-guide/_images/webclient_add-to-basket.jpg

client/html/user-guide/_images/webclient_basket1.jpg

client/html/user-guide/_images/webclient_basket2.jpg

client/html/user-guide/_images/webclient_coordinates.jpg

client/html/user-guide/_images/webclient_current-view.jpg

client/html/user-guide/_images/webclient_details_display.jpg