Global: Cleanup README, add INSTALL with better build-instructions

INSTALL

+Build on Debian and Ubuntu based distributions
+==============================================
+Tested on:
+* Ubuntu Trusty
+* Ubuntu Vivid
+* ElementaryOS Freya
+* Linux Mint Rebecca Cinnamon
+
+$ sudo apt-get install build-essential autoconf libtool intltool ppp-dev git xl2tpd openswan libglib2.0-dev libdbus-glib-1-dev libnm-util-dev libnm-glib-vpn-dev libgnome-keyring-dev libgtk-3-dev
+$ export GIT_SSL_NO_VERIFY=1
+$ git clone https://git.cryptopath.org/cerial/NetworkManager-l2tp.git
+$ cd NetworkManager-l2tp/
+$ ./autogen.sh
+
+The Debian and Ubuntu GNOME packages don't have reasonable defaults,
+so you have to give ./configure every path manually:
+
+$ ./configure \
+	--prefix=/usr --localstatedir=/etc --sysconfdir=/etc \
+	--sharedstatedir=/var/lib --libexecdir=/usr/lib/NetworkManager \
+	--infodir=/usr/share/info --mandir=/usr/share/man \
+	--with-pppd-plugin-dir=/usr/lib/pppd/2.4.5
+
+$ make
+$ sudo make install
+
+$ sudo update-rc.d xl2tpd disable #!!!!
+$ sudo service xl2tpd stop #!!!!
+
+Place certifcates is correct directories.
+PLEASE NOTE: Private userkey has to be same name as public user key (for now)!!
+
+Reboot or restart NetworkManager

README

@@ -3,27 +3,19 @@ IPSec-L2TP support for NetworkManager
 
 Uses xl2tpd and (optional) strongswan.
 
-Build
-=====
 
-    ./autogen.sh
-    ./configure  # (optional)
-    make
-    sudo make install
+Create Connection (DELETEME)
+============================
 
-Debian and Ubuntu
-=================
+Name: bd4travel IPSec-L2TP-VPN
+Gateway: vpn.bd4travel.de
+User Name: USERNAME
+Password: CHAP_PASSWORD
 
-The Debian and Ubuntu GNOME packages don't have reasonable defaults,
-so you have to give ./configure every path manually.
+IPSec-Settings:
+- Enable tunnel
+- Gateway-Id: C=DE, ST=Hessen, L=Eschborn, O=bd4travel, CN=bd4travel IPsec Gateway, E=certs@bd4travel.com
+- Private key file: USERNAME.pem
 
-  ./configure \
-	--prefix=/usr --localstatedir=/etc --sysconfdir=/etc \
-	--sharedstatedir=/var/lib --libexecdir=/usr/lib/NetworkManager \
-	--infodir=/usr/share/info --mandir=/usr/share/man \
-	--with-pppd-plugin-dir=/usr/lib/pppd/2.4.5 \
-	--with-dist-version=<my_build_ver>
-
-You'll need at least the following installed:
-
-  sudo apt-get install xl2tpd strongswan
+PPP-Settings:
+Only enable MSCHAPv2, everything else default.