Fix Jira issue #ROOT-6191: TBrowser and canvas editor

Embed the Pad Editor in the left tab of the browser instead of in the canvas itself, as suggested by Axel in the Jira issue #ROOT-6191
Fix Jira issue #ROOT-6221: Text editor does not allow negative positions

Apply patch kindly sent by Matthew Strait
Unanamed macros not detecting leading and trailing comments. (ROOT-5930 and ROOT-4791).
Multiple line of leading comments. (ROOT-5930 and ROOT-4791).
Only complain about inspecting std classes for persistent members.
Give libCling an extension.
Fix warning on Windows
Fix warnings on windows
Lazy TListOf* speed up checking where there was a change in the AST.
TAlienFile::Open passes now to the server the content of ALIEN_SITE variable if this is defined (Costin Grigoras)
(cherry picked from commit 9f0ae59c920193f6e2dce405dca5051ea9a2011e)
Fixed data race in TGeoPgon
(cherry picked from commit f3a25819d09192fa5bf9c4608ffc541d86f968af)
Improve the data members comments
access to arrays of objects data
Since std::to_string is now used in several other places, no need to comment it out anymore (it is still missing with gcc 4.8-2 on cygwin)
TDavixFile changes : - fix ROOTTest executions problem : remove failed word from warning message - gridMode considers now CAPath correctly - correct problem related to X509_CERT_DIR and gridmode

Signed-off-by: Fons Rademakers <Fons.Rademakers@cern.ch>
fix whitespace and tabs.
Fix documentation for TEveProjected::GetProjectedAsElement(), see ROOT-6246.

(cherry picked from v5-34-00-patches commit 746a973aaf828c2be57b97336ee9c1f21ff29199)
Document the fact that ~TEveElement should not be invoked directly, see ROOT-6247.

(cherry picked from v5-34-00-patches commit 0c5e70a2e44cb9f0370cb936ad84824645f92761)
Trailing whitespace cleanup.
Indentation.