[models] Harmonized style for BAT header includes

Prerequisite for new dictionary generation scheme
[fix] Added a missing namespace std prefix
[upgrade] Removed use of functionality no longer available in ROOT-6

ROOT-6 doesn't provide TH1::Integral(a, b, params , ...)
[build] Made build compatible with ROOT-6 (and ROOT-5)

New LinkDef-based dictionary generation scheme with automatic
rootmap-file generation. Uses rootcint for ROOT-5 and rootcling for
ROOT-6
[build] Passing through ROOTAUXCFLAGS to build and bat-config

ROOTAUXCFLAGS can contain important flags like `std=c++11`.
[models/base] Fix build with roostats
[configure] Fix output files that are not part of the distribution
[tools] Remove map_solibs.sh
[install] Update instructions: we now support ROOT6
[build] Fix indentation in Makefile.am
[examples] Improve polynomialfit's clean
[install] Add comment on ubuntu root packages
[gitignore] Remove LinkDef.h from git (created on the fly), separate gitignore for examples/
[build] Run spellchecker on INSTALL and README
[build] Fix cuba installation instructions
[cuba] Support 3.3 and 4.0. Drop 3.2 support.
[configure] Infer cuba directory from partview
[configure] don't assume cuba's partview exists
[build] Removed rootmap files (now generated during build) from dist
[build] Fixed ROOT dictionary creation for models/base

* BATCalculator contains a ClassDef, so needs a "+" in the LinkDef
  pragma.

* BATCalculatorLinkDef.h is obsolete and was replaced by
  LDef_roostats.h.

* Fixed header guards in LinkDef files in models/base.