Update for OpenQuake-engine v1.2

Updated contents to reflect changes in OpenQuake-engine v1.2.
Added structure.tex for the new template.
Changed configuration.tex to match the Hazard Book.
Added a LICENSE file.
Updated license to CC BY-NC-SA 4.0 (from 3.0).
Updated the title page.
Updated the copyright page.
Added a preface page.
Moved all old and unused files to the archive folder.
Modified structure.tex to style parts and subsubsections in the table
of contents.
Added build.sh with list of commands to build the pdf.
Added clean.sh to remove all auxiliary files produced by pdflatex.
Converted all .eps figures to .pdf to reduce file size and compilation
issues.