Move each evaluation class in its each own file, rename Eval class.

Using plain style doesn't work because all other libraries
now use all-keyword calls to target_link_libraries().

We only use 32-bit builds on Windows, so this warning is just an
annoyance since it cannot be turned OFF.

This was updated in commit fe4ffa75,
but that commit only changed this on UNIX and missed Windows.

Issue: ROOT-9532

Visual Studio 2017 doesn't use the registry anymore, so no need to try to find keys. This prevent picking wrong directories in the case there is another version installed on the computer, and prevent also the following errors when starting ROOT:
  RegQueryValueEx: returned 2: The system cannot find the file specified.
  RegOpenKeyEx: returned 2: The system cannot find the file specified.

(cherry picked from commit f4801313)

(cherry picked from commit 9482a9e0e4459e783700cb916e77248fa373e41b)

This reverts commit 316f5535.

consider only ROOT 6.14 and 6.12 removing 6.10 and 5.34.

in order for the citer to select the right link to add to the citation.

- add example usages to Filter, Define, Snapshot
- add some links to other parts of the documentation where relevant
- small fixes here and there