realtek-rtl8723be fix for ubuntu

01. Command Terminal:

-iwconfig
: Collect wlp2s0

02. Copy the package into desktop then extract there.
    (http://connectwww.com/how-to-solve-realtek-rtl8723be-weak-wifi-signal-problem-in-ubuntu/4625/)

03. Command Terminal:

-cd Desktop
-cd rtlwifi_new-rock.new_btcoex
-make (then wait for a while)
-sudo make install (give the pass)
-sudo modprobe -rv rtl8723be
-sudo modprobe -v rtl8723be ant_sel=2
-sudo ip link set wlp2s0 up
-sudo iw dev wlp2s0 scan (it'll scan all networks with signal strengths)
-echo "options rtl8723be ant_sel=2" | sudo tee /etc/modprobe.d/50-rtl8723be.conf
    (to make things permanent)