Various fixes for JIRA tickets

NSM-262 Add link to web service overview on wiki page
NSM-259 Fix daily data file header txt
NSM-255 update legend labels
NSM-251 Add download feature to web interface - fix download window refresh
NSM-249 Reconfigure the downloaded file format for daily sediment and flow data - fix daily data split issue
NSM-196 NLCD layer not loading in the application