Merge r1752331, r1752332, r1752333 from trunk:

CMake: use CMAKE_REQUIRED_INCLUDES to find APR macros

When using CMake with Visual Studio on Windows, invoking the
CHECK_SYMBOL_EXISTS macro with the full paths to the include files seems
to always result in failure.

Instead, use the documented CMAKE_REQUIRED_INCLUDES variable to set the
include directory, and pass only the headers' base names to
CHECK_SYMBOL_EXISTS.

CMake: use generator expressions to find output files

Multi-configuration generators, like Visual Studio, use a different
output directory (Debug, Release, etc.) for each configuration. To find
the output files reliably, switch to using generator expressions instead
of hardcoding the file paths for PDBs, export files, etc.

CMake: quote installation paths

Deal with installation paths with spaces in them (e.g. "C:\Program
Files") by quoting the arguments to perl and xcopy.
Submitted by: jchampion
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1770674 13f79535-47bb-0310-9956-ffa450edef68