Cleanup README and add official IRC channel and mailing list.
Cleanup README and add official IRC channel and mailing list.

JerryScript-DCO-1.0-Signed-off-by: Tilmann Scheller t.scheller@samsung.com

grgustaf/jerryscript,zherczeg/jerryscript,LeeHayun/jerryscript,tilmannOSG/jerryscript,robertsipka/jerryscript,bsdelf/jerryscript,glistening/jerryscript,martijnthe/jerryscript,jerryscript-project/jerryscript,jack60504/jerryscript,gabrielschulhof/jerryscript,zherczeg/jerryscript,bsdelf/jerryscript,loki04/jerryscript,dbatyai/jerryscript,bzsolt/jerryscript,tilmannOSG/jerryscript,LeeHayun/jerryscript,dbatyai/jerryscript,gabrielschulhof/jerryscript,LaszloLango/jerryscript,zherczeg/jerryscript,LeeHayun/jerryscript,robertsipka/jerryscript,robertsipka/jerryscript,LeeHayun/jerryscript,zherczeg/jerryscript,bzsolt/jerryscript,akosthekiss/jerryscript,jack60504/jerryscript,bzsolt/jerryscript,zherczeg/jerryscript,jerryscript-project/jerryscript,gabrielschulhof/jerryscript,martijnthe/jerryscript,slaff/jerryscript,gabrielschulhof/jerryscript,grgustaf/jerryscript,martijnthe/jerryscript,yichoi/jerryscript,glistening/jerryscript,glistening/jerryscript,jack60504/jerryscript,glistening/jerryscript,robertsipka/jerryscript,akosthekiss/jerryscript,bsdelf/jerryscript,bzsolt/jerryscript,bzsolt/jerryscript,jack60504/jerryscript,jack60504/jerryscript,jack60504/jerryscript,slaff/jerryscript,slaff/jerryscript,slaff/jerryscript,tilmannOSG/jerryscript,loki04/jerryscript,jerryscript-project/jerryscript,grgustaf/jerryscript,tilmannOSG/jerryscript,dbatyai/jerryscript,yichoi/jerryscript,dbatyai/jerryscript,jerryscript-project/jerryscript,glistening/jerryscript,bsdelf/jerryscript,tilmannOSG/jerryscript,grgustaf/jerryscript,bsdelf/jerryscript,LaszloLango/jerryscript,slaff/jerryscript,LeeHayun/jerryscript,loki04/jerryscript,LaszloLango/jerryscript,glistening/jerryscript,akosthekiss/jerryscript,martijnthe/jerryscript,akosthekiss/jerryscript,grgustaf/jerryscript,yichoi/jerryscript,LaszloLango/jerryscript,yichoi/jerryscript,martijnthe/jerryscript,akosthekiss/jerryscript,LaszloLango/jerryscript,robertsipka/jerryscript,loki04/jerryscript,jerryscript-project/jerryscript,loki04/jerryscript,martijnthe/jerryscript,loki04/jerryscript,robertsipka/jerryscript,bsdelf/jerryscript,yichoi/jerryscript,dbatyai/jerryscript,grgustaf/jerryscript,gabrielschulhof/jerryscript