To get the Netgear A6100 working on a clean raspbian / already existing install do the following (for raspberry pi 2, but easy to adapt for rpi1)

sudo apt-get update
sudo apt-get install linux-headers-rpi2-rpfv linux-image-rpi2-rpfv

After install append the following in /boot/config.txt:

kernel=vmlinuz-3.18.0-trunk-rpi2
initramfs initrd.img-3.18.0-trunk-rpi2

After a reboot, check if kernel has switched to 3.18.0-trunk-rpi2:

uname -r

Then download and install the following https://github.com/abperiasamy/rtl8812AU_8821AU_linux:

git clone [email protected]:abperiasamy/rtl8812AU_8821AU_linux.git
cd rtl8812AU_8821AU_linux
make
sudo make install
sudo modprobe 8812au

Reboot and check if a wifi scan works:

sudo iwlist wlan0 scan

Find the access point you want connect to and append the ESSID and password to /etc/wpa_supplicant/wpa_supplicant.conf:

network={
    ssid="The_ESSID_from_earlier"
    psk="Your_wifi_password"
}

Reboot and enjoy your internet !