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

Patch provided by Oliver Freyermuth.
The version 1.2.23 of libpng was the built-in version in ROOT. It had some security issuee. Now we have 1.2.50.
cf: https://sft.its.cern.ch/jira/browse/ROOT-5322
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.
Fix hanging context menu for TQtWidget canvas. Fixes ROOT-4031.
ignore tutorials/tree/basic.root.
Added paranthesys around expressions multiplied by units so that the unit applies to a combined tag and not only to the last term
import the mods (from the trunk) allowing to change the line attributes for legos. As suggested here :
http://root.cern.ch/phpBB3/viewtopic.php?f=3&t=16560
Adding enum to TBranchElement to clarify Type numbers

(cherry picked from commit caec9c2a21b520cd456041b77fcda0b52d8ab286)

Conflicts:
	tree/treeplayer/src/TTreeReaderValue.cxx
Added method to get the size of the class

(cherry picked from commit beafe941588df210e50d209fc951bcace6181a1f)
Fix TClass::GetClassSize() to also work for CollectionProxy case: use Size().

(cherry picked from commit 6fecd500190c9f08edd6f2e03c5cf5ec8770d707)
Remove stray "," in enum constant list.
Added enums for sub-branches of STL and Clones, and moved Class getter to being public

(cherry picked from commit bafd944e918a05824d6afc7344fdc70cfc153103)

Conflicts:
	tree/tree/inc/TBranchElement.h
	tree/treeplayer/src/TTreeReaderArray.cxx
	tree/treeplayer/test/hardTreeReaderTest.cpp
Coding convention; rename some enum constants.
Fix for ROOT-5280
THistPainter and TPainter3DAlgorithms are now the same in 5.34 and 6.00
TPad::Print did not acknowledge for the first creation of the PNG files
Fixed constness of array arguments to navigation methods in solids. Added method stubs for shape navigation API, implemented as loops - to be overwritten by shapes.