[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* BATCalculatorLinkDef.h is obsolete and was replaced by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.
[doc] Replace eps bat icon with pdf to fix `make dist` with older pdflatex versions
[cuba] Bugfix configure and compile

o remove a typo when searching for partview
o fix `invalid conversion to non-const` that breaks cuba4 build on some compilers
[examples] Bugfix std include in polynomialfit
[models] bugfix roostats library dependency

o remove unnecessary cuba linking
[models] Inform libtool about libBAT dependency
[build] Fixed ROOT dictionary generation for ROOT v6.02.00 or newer
[build] Fixed ROOT dictionary adjustments for out-of-tree builds
[examples] Fix conditional includes for root 6.02 compatibility

o add missing includes in mcstat.C
[install] Beautify code highlighting
[install] Add paragraph on root 6 and interpreted macros
[src, models] Remove useless `clean-local` and `.o: .cxx` rules from Makefile.am

Use CLEANFILES to remove single files, and automake knows very well how to compile a file
[build] Fixed dictionary generation for models/base with rootstats

LDef_rootstats.h contained "pragma link off" statements that invalidated
all previous pragma link statements in LDef.h .
[test] Relocate unit tests to top-level directory, add to dist

Clean up output file handling: always store them in BAT_TESTDIR
[build] Update readme.devel and add to dist