Update NEWS file with a summary for 2.6.3
Update NEWS file with a summary for 2.6.3

vsmontalvao/liblouis,BueVest/liblouis,BueVest/liblouis,BueVest/liblouis,liblouis/liblouis,BueVest/liblouis,hammera/liblouis,vsmontalvao/liblouis,vsmontalvao/liblouis,IndexBraille/liblouis,IndexBraille/liblouis,hammera/liblouis,hammera/liblouis,liblouis/liblouis,vsmontalvao/liblouis,IndexBraille/liblouis,IndexBraille/liblouis,vsmontalvao/liblouis,BueVest/liblouis,hammera/liblouis,hammera/liblouis,liblouis/liblouis,IndexBraille/liblouis,liblouis/liblouis,liblouis/liblouis,liblouis/liblouis,BueVest/liblouis,hammera/liblouis