fix genome group and feature group download links; PATRIC3/patric3_website#1255
fix genome group and feature group download links; PATRIC3/patric3_website#1255

Also:
- avoid unnecessary error on download tooltip
- "DWNLD" text consistency

dmachi/p3_web,dmachi/p3_web,dmachi/p3_web,nconrad/p3_web,PATRIC3/p3_web,aswarren/p3_web,maovt/p3_web,nconrad/p3_web,PATRIC3/p3_web,maovt/p3_web,zreyn/p3_web,hyoo/p3_web,nconrad/p3_web,dawenx/p3_web,dawenx/p3_web,zreyn/p3_web,dawenx/p3_web,hyoo/p3_web,dawenx/p3_web,aswarren/p3_web,dmachi/p3_web,aswarren/p3_web,PATRIC3/p3_web,maovt/p3_web,zreyn/p3_web,maovt/p3_web,PATRIC3/p3_web,aswarren/p3_web,zreyn/p3_web,hyoo/p3_web,nconrad/p3_web,hyoo/p3_web