Update install_pyptv_ubuntu.md

added "make cmake and python-Enable"  to the packages list
(for some reason I needed to get python-Enable even though it is in the list of ets packages)

in liboptv installation deleted autoreconf and ./configure and added cmake -G "Unix Makefile" -i

in openptv-python git clone changed the path from alexlib to OpenPTV
Update install_pyptv_ubuntu.md
Update install_pyptv_ubuntu.md

deleted autoconf package from the apt-get line
merged Yulia patch for the set of packages to install on Ubuntu 12.04