Set HighDPI environment for Eclipse

To make Eclipse work well in the HighDPI environment in Linux, it needs to do the following configuration:

1. Make the font look bigger (reference page): run eclipse with the environment variable GDK_DPI_SCALE.

   On GTK, the standard way to configure scaling for a single application is to set the GDK_DPI_SCALE environment variable before launching an application. E.g. to set the scale factor to 150% on the command line when launching Eclipse:

    $ GDK_DPI_SCALE=1.5 ./eclipse
   

2. Make icons look bigger (reference page): edit $ECLIPSE_HOME/eclipse.ini and add the following lines to the file:

    -Dswt.enable.autoScale=true
    -Dswt.autoScale=200
    -Dswt.autoScale.method=nearest
   

Restart the eclipse and it works!

Tested on Eclipse 4.7.2.