updated .gitignore to fix over aggressive pattern for Icon folders automatically generated on Mac OSX
updated .gitignore to fix over aggressive pattern for Icon folders automatically generated on Mac OSX

Unidata/netcdf-java,Unidata/netcdf-java,Unidata/netcdf-java,Unidata/netcdf-java,Unidata/netcdf-java,Unidata/netcdf-java,Unidata/netcdf-java