FindMPI: Append MPI C++ library correctly in non-compiler case (#12874)

When we have no MPI compiler wrapper and search explicitly for the MPI
C++ library append it correctly to the list of libraries instead of
using a space.

Suggested-by: Mourad Boufarguine <bouffa@gmail.com>
CheckSymbolExists: force the compiler to keep the referenced symbol

Otherwise the compiler may optimize out the reference to the symbol as the
previous version was not really using this. This leads to symbols that are
only in a header but not in the given libraries to be reported as present.

This came up on the first try to fix bug 11333 as "gcc -O3" would optimize
out the reference to pthread_create() so the correct library the symbol is in
was not detected.

The new test code was suggested by Brad King.
add a test for Check{,CXX}SymbolExists

Now that we think that CheckSymbolExists really works for all cases it is time
to prove that. If this code fails too many other things will break.
Merge topic 'link-shared-depend-cycle-issue-12647' into check_symbol_exists
add a test that loops through most Find* modules

This allows easy spotting of modules that output crappy messages and the
like.
KWSys Nightly Date Stamp
Merge branch 'master' of git://cmake.org/cmake into openssl-version
FindOpenSSL: only try to parse opensslv.h if it exists
cmInstallCommand: Fix indentation error

A large block of code was indented 2 spaces less than it should.
cmInstallCommand: Remove duplicated sentence from docs

install(TARGETS ...) documentation described twice what happens on non-DLL
systems.
FindOpenSSL: also parse version number define with uppercase letters
AllFindModules test: keep complete output
cmInstallCommand: Fix line length for style

After indentation was fixed by a previous commit some lines became too
long.  Re-wrap to shorten them.
Merge topic 'bootstrap-options'

c19868b bootstrap: Forward options after '--' to cmake
f39e82c bootstrap: Re-implement command line option processing
dbf05f7 bootstrap: Update copyright year in version report
Merge topic 'vs10-fix-pdbname-issue-12328'

655a7dd VS10: Fix /pdb option vcxproj element name (#12328)
Merge topic 'FindPythonLibs-single-user-issue-12869'

a04ced3 FindPythonLibs: Search for single-user installs on Windows
Merge topic 'compiler-version'

0df1942 Detect SGI MIPSpro compiler version with its id
a5e892c Document compiler version macro formats used for detection
d7c6f41 Detect HP compiler version with its id
3dd9fa9 Detect SunPro compiler version with its id
c198730 Detect Watcom compiler version with its id
5899b98 Detect Clang compiler version with its id
b8cfa65 Detect PGI compiler version with its id
6dae666 Detect IBM XL compiler version with its id
4080d55 Detect Borland compiler version with its id
2cc205a Detect Intel compiler version with its id (#11937)
a6d83cc Detect MSVC compiler version with its id
a662855 Detect GNU compiler version with its id (#6251)
fa7141f Add framework to detect compiler version with its id (#12408)
Merge topic 'ExternalProject-git-cmd-version'

4ac6ba2 ExternalProject: Update copyright year
8cb8ccc ExternalProject: Fix git.cmd version detection
Merge topic 'fixSymlinkInZIP'

768cf91 Do not add the content of a file if it's a symlink.
Merge topic 'cm-bzip2-header-issue-10950'

d4a9e33 Include bzlib.h consistently across CMake build (#10950)