Merge branch 'backport-doc-find-module-no-summary' into release
FindQt4: Fix handling of QT_VERSION_MAJOR mismatch

Fix capitalization of Qt4_FOUND variable when setting it to false in
this case.  This caused find_package(Qt4) to appear successful when it
was not.  Note that the legacy QT4_FOUND variable is unconditionally
overwritten at the end of the file with the value of Qt4_FOUND.
ctest: count errors from scripts properly

In the unlikely event that someone has a billion+ scripts (or some
codepath returns negative numbers), we could overflow and make a pile of
errors a non-error. This change also allows us to use flags for the
error in the future rather than just "something went wrong".
Rename header guards to not start with double underscore

Use regex to find/replace:

__(cm.*_h)
\1

Then fix QCMake.h by hand.
FindMPI: search for msmpi's mpiexec as well
Help: Extend policy CMP0054 documentation with an example
Merge branch 'doc-CMP0054-example' into release
Merge topic 'doc-CMP0054-example'

f2f1c95d Help: Extend policy CMP0054 documentation with an example
Merge topic 'drop-double-underscores'

111be180 Rename header guards to not start with double underscore
Merge topic 'FindQt4-fix-major-version-mismatch'

009c1865 FindQt4: Fix handling of QT_VERSION_MAJOR mismatch
Merge topic 'catch-ctest-errors-better'

d8589e64 ctest: count errors from scripts properly
Merge topic 'find-msmpi'

17a846ac FindMPI: search for msmpi's mpiexec as well
Merge branch 'release'