Fix compilation problem for sqlite versions between 3.5.0-3.7.7. ROOT-5318.

Patch provided by Oliver Freyermuth.
Disable asserts until whetever triggers them gets fixed.
Simplify some rules and and protect pdflatex which return 1 even on succes on OSX.
whitespace.
ignore intermediate latex files produced by pdflatex.
The version 1.2.23 of libpng was the built-in version in ROOT. It had some security issues. Now we have 1.2.50.
cf: https://sft.its.cern.ch/jira/browse/ROOT-5322
o) special case __setitem__ for std::vector<bool>
o) optimization: prevent double lookup in global namespace (gRootModule)
o) support for global templated classes
More correct storage format for timestamps. Fix ROOT-5330.

Solution attached as patch:
- SetTimestamp() writes timestamps of the format "2013-06-30 05:11:01.021"
  to the database and communicates the 3-digit precision (i.e., milliseconds)
  to the user in its comment. 3 digit precision is also what the strftime /
  datetime methods of sqlite use, all other digits are ignored by those methods.
- GetTimestamp() reads such timestamps, also limiting the fraction-precision
  to 3 digits and communicating that to the user from within the comment.

Patch by Oliver Freyermuth.
More correct storage format for timestamps. Fix ROOT-5331.

Solution attached as patch:
- SetTimestamp() writes timestamps of the format "2013-06-30 05:11:01.021"
  to the database and communicates the 3-digit precision (i.e., milliseconds)
  to the user in its comment. 3 digit precision is also what the strftime /
  datetime methods of sqlite use, all other digits are ignored by those methods.
- GetTimestamp() reads such timestamps, also limiting the fraction-precision
  to 3 digits and communicating that to the user from within the comment.

Patch by Oliver Freyermuth.
zlib should be included from a different place on windows.
fix coverity issue.
Generate the doc as separated pdf files. One per chapter.
generate the doc splitted info chapters in HTML format. Available here http://root.cern.ch/drupal/content/users-guide