fix some URLs, internal links, fix un visible tables: Closes #5

Signed-off-by: Sebastien Goasguen <runseb@gmail.com>
Update installation.rst

Updated the paths to cloud-install-sys-tmplt
Updated links to system templates using values from the upgrade from 4.2.1 to 4.3 release notes

This closes #6
Merge remote-tracking branch 'upstream/master'
fixed links in hypervisor_installation, installation, network_setup